I have noticed that there are a few discrepancies that arise by the new summarized version of the 13 principles that I must tell you WAS NOT written by the Rambam.

(Colloquially known today as the Ani Maamin)

Not to mention that each summary of the 13 (ironically) change depending on the organization that publishes them.

For example:

Mechon Mamre
1.God exists
2.God is one and unique
3.God is incorporeal
4.God is eternal
5.Prayer is to be directed to God alone and to no other
6.The words of the prophets are true
7.Moses' prophecy is better than any other prophet's
8.The Written Torah (first 5 books of the Bible) and Oral Torah.
9.There will be no other Torah
10.God knows the thoughts and deeds of men
11.God will reward the good and punish the wicked
12.The Mashiach will come
13.The dead will be resurrected
 
Chabad
1. Belief in the existence of the Creator, who is perfect in every manner of existence and is the Primary Cause of all that exists.
2. The belief in G-d's absolute and unparalleled unity.
3. The belief in G-d's non-corporeality, nor that He will be affected by any physical occurrences, such as movement, or rest, or dwelling.
4. The belief in G-d's eternity.
5. The imperative to worship G-d exclusively and no foreign false gods.
6. The belief that G-d communicates with man through prophecy.
7. The belief in the primacy of the prophecy of Moses our teacher.
8. The belief in the divine origin of the Torah.
9. The belief in the immutability of the Torah.
10. The belief in G-d's omniscience and providence.
11. The belief in divine reward and retribution.
12. The belief in the arrival of the Messiah and the messianic era.
13. The belief in the resurrection of the dead.
 
Even the title that is used now a days was never used by the Rambam for the 13 principles known as the Ani Maamin.
 

Below is a translation of the 13 principles as it appears in the Rambam's Hakdama to Perek Chelek..

 
The First Fundamental Principle: To believe in the existence of the Creator; that there is an Existent complete in all the senses of the word “existence.” He is the cause of all existence. In Him all else subsists and from Him derives. It is conceivable that He not exist, for should He not exist the existence of all else would be extinguished, and nothing could persist. If we imagine the absence of any other existent thing, however, God’s existence would not thereby be extinguished or diminished. For unity and mastery are only God’s, since He is sufficient to Himself. All else, whether angels or celestials and whatever is in them or below them, needs Him to exist. This first fundamental principle is taught in the Biblical verse: “I am the Lord your God” (Ex. 20:2). The Second Fundamental Principle: We are told to believe that God is one, the cause of all oneness. He is not like a member of a pair, nor a species of a genus, nor a person divided into many discrete elements. Nor is He one in the sense that a simple body is, numerically one but still infinitely divisible. God, rather, is uniquely one.
 
This second fundamental principle is taught in the Biblical verse: “Hear, O Israel, the Lord our God, the Lord is One” (Deut. 6:4). Maimonides Introduction to Perek Helek 18 The Third Fundamental principle: We are to believe that he is incorporeal, that His unity is physical neither potentially nor actually. None of the attributes of matter can be predicated of Him, neither motion, nor rest for example. They cannot refer to Him accidentally or essentially. That is why our sages denied Him composition and separation, and said : “On high there is neither sitting nor standing, neither want nor weariness” (Hagigah 15a), i.e., neither composition nor separation, and said: “On High there is neither sitting nor standing, neither want nor weariness” (Hagigah 15a), i.e., neither composition nor separation, as the Biblical usage of these words attests. The prophet asked: “To whom can you compare God, whom might he resemble?” (Is. 40:18). If He were a body, He would be like other bodies. Whenever Scripture describes Him im corporeal terms like walking, standing, sitting, speaking, and the like, it speaks metaphorically. Thus our sages said: “The Torah speaks in human language” (Berakhot 31b). This third fundamental principle is taught in the Biblical verse: “You have seen no image” (Deut. 4:15). This verse means to say, one cannot conceive of Him as one would a Baal image, since, as we have shown, He has no body at all, actually or potentially.
 
The Fourth Fundamental Principle: We are to believe that the One is absolutely eternal, no thing exist before Him, as many Scriptural verses prove. This fourth fundamental principle is taught in the Biblical verse: “A dwelling-place is the Eternal God” (Deut. 33:27). The Fifth Fundamental Principle: Only He, blessed be He, is rightfully worshipped, magnified, and obeyed. One must not pray to anything beneath Him in existence: angels, stars, planets or elements, or anything composed of these. All of them are natural processes without self-determination or free will. Only God is free and puissant. Hence, we must not worship those powers which can serve only as means to bring us nearer to Him. We must think only of Him, leaving to one side all else. The fifth fundamental principle has all Biblical warning against idolatry as its warrant, in other words, the bulk of the Torah.
 
The Sixth Fundamental Principle is Prophecy. One should know that among men are found certain people so gifted and perfected that they can receive pure intellectual form. Their human intellect clings to the Active Intellect, whither it is gloriously raised. These men are the prophets; that is what prophecy is. A full explanation of this root principle would require much more time. We do not wish to cite proof-texts for every principle or to explain each fully. However, I remind you in passing of the many Scriptural passages which testify to the prophecy of many different prophets.
 
 
The Seventh Fundamental Principle is the prophecy of Moses our Teacher. We are to believe that he was the chief of all other prophets before and after him, all of whom were his inferiors. He was the chosen one of all mankind, superior in attaining the knowledge of God to any other person who ever lived or ever will live. He surpassed the normal human condition and attained the angelic. There remained no veil he did not rend and penetrate behind, nothing physical to hold him back, no deficiency, great or small, to confuse him. All his powers of sense and fantasy were repressed, and pure reason alone remained. This is what is meant by saying that he spoke to God without angelic mediation. I should have wished to explicate this mystery from Biblical sources, explaining such verses as “God spoke to Moses mouth to mouth” (Num. 12:8), but I see they would require a great many preparatory comments about the remarkable existence of angels, which derives from God, and about the powers of the soul. And the discussion would have to be widened to include the prophetic descriptions of God and angels, including the Divine Dimensions of which even the briefest description would require a hundred pages. I have, therefore, left these matters to my exegetical book, the book on prophecy on which I am working, or to a book I hope some day to write explaining these fundamental issues. Returning to our seventh fundamental principle: Moses’ prophecy must be distinguished from that of all other prophets in four respects: Maimonides Introduction to Perek Helek 20 1. All other prophets were addressed by God through intermediaries, only Moses immediately. This is indicated by the phrase, “mouth to mouth I addressed Him.” 2. Prophecy came to all others in sleep (cf. the verses which refer to “a dream of night” [Gen. 20:3]; “a vision of night” [Job. 33:15]), or in daytime when a trance fell on the prophet so that his senses and intellect would be as useless as in a dream. This state is called “vision” or “insight” as in the expression “visions of God.” But the Words came to Moses in broad daylight when he stood by the two cherubs, as God had promised, “I will meet you there” (Ex. 25:22). God said: “Moses, my servant, is not like other prophets; to him alone I speak mouth to mouth.” 3. Even if another prophet should receive a vision of God through an angel, his powers would fail; he would be overcome with dread, and nearly lose his mind. When, for example, Daniel was addressed by Gabriel in a vision, he said: “I had no strength; my vigor turned against me, I retained no power, but fell swooning on my face to the ground, writing in a vision” (Dan. 10:8 ff., 10:16). This never happened to Moses. When the Word came to him he would neither shiver nor tremble. “God spoke to Moses face to face, as a man to his friend” (Ex. 33:11). This means that, since a friendly talk produces no anxiety, Moses had no fear. Face to face with God, he had no terror of the revelation, because he clung to Him in a wholly conscious way, as we have implied. 4. The other prophets could not attain a vision whenever they pleased. All depended on God’s will. A prophet might wait days or years before prophecy would come to him. He would beg God to reveal Himself in prophecy, but he would have to wait for days or months before the prophecy came. Sometimes God would not reveal Himself at all. There were many sects who prepared themselves by purifying their minds as Elisha did-“and now take me a musician that prophecy might reach me” (II Kings 3:15). But prophecy did not necessarily follow their preparation. Moses our Teacher, on the other hand, could say whenever he wished: Maimonides Introduction to Perek Helek 21 “Wait, and I shall hear what the Lord commands you” (Num. 9:8). Scripture says: “Tell Aaron, your brother, not to enter the holy place anytime at all” (Lev. 16:2). Our sages interpret this to mean that Aaron could not come to God whenever he pleased, but Moses might (Midrash to Ahare Mot).
 
The Eighth Fundamental Principle is that the Torah came from God. We are to believe that the whole Torah was given us through Moses our Teacher entirely from God. When we call the Torah “God’s Word” we speak metaphorically. We do not know exactly how it reached us, but only that it came to us through Moses who acted like a secretary taking dictation. He wrote down the events of the time and the commandments, for which reason he is called “Lawgiver.” There is no distinction between a verse of Scripture like “The sons of Ham were Cush and Mizraim” (Gen. 10:6), or “His wife’s name was Mehetabel and his concubine was Timna” (Gen. 36:39,12), and one like “I am the Lord your God, and all are the Torah of God, perfect, pure, holy and true. Anyone who says Moses wrote some passages on his own is regarded by our sages as an atheist of the worst kind of heretic, because he tries to distinguished essence from accident in Torah. Such a heretic claims that some historical passages or stories are trivial inventions of Moses and not Divine Revelation. But the sage said that if one accepts as revelation the whole Torah with the exception of even one verse, which Moses himself and not God composed, he is referred to in the verse, “he has shamed the Word of the Lord” (Num. 15:31), and is heretical. Every word of Torah is full of wisdom and wonders for one who understands it. It is beyond human understanding. It is broader than the earth and wider than the sea. Each man must follow David, anointed of the God of Jacob, who prayed: “Open my eyes that I may behold wonders out of Your Torah” (Ps. 119:18). The authoritative commentary on the Torah is also the Word of God. The sukkah we build today, or the lulay, shofar, fringes, phylacteries, etc. we use, replicate exactly those God showed Moses which Moses faithfully described for us. This fundamental principle is taught by the verse: “And Moses said, ‘ 22 shall you know that then Lord sent me to do all these things, and that they are not products of my own mind’” (Num. 16:28). The Ninth Fundamental Principle is the authenticity of the Torah, i.e., that this Torah was precisely transcribed from God and no one else. To the Torah, oral and written, nothing must be added nor anything taken from it, as is said, “You must neither add nor detract”(Deut. 13:1).We have already sufficiently explained this principle in our introduction to this Commentary on the Mishnah.
 
The Tenth Fundamental Principle is that God knows all that men do and never turns His eyes away from them, as those who say “The Lord has abandoned this earth”(Ezek.8:12, 9:9)claim. Rather, as Scripture has it, “Great in counsel, mighty in insight (is God) whose eyes are open to all the ways of men”(Jer. 32:19), or the Lord saw that great was the evil of man on earth”(Gen.6:5), or the verse, “The cry of Sodom and Gomorrah is powerful” (ibid. 18:20).All these citations point to our Tenth Fundamental Principle.
 
The Eleventh Fundamental Principle is that God rewards those who perform the commandments of the Torah and punishes those who transgress its admonitions. The greatest reward is the world to com; the worst punishment is extinction. We have already made this sufficiently clear. The Scripture which teaches this fundamental principle is “If you will not forgive their sin, extinguish me.” To which God replied, “I will expunge from My book only the man who has sinned against Me” (Ex.32:32 ff.). This proves He knows both the obedient and the sinner, and rewards or punishes each.
 
The Twelfth Fundamental Principle refers to the Messianic Era. We are to believe as fact that the messiah will come and not consider him late. If he delays, wait for him (Hab. 2:3); set no time limit for his coming. One must not make conjectures based on Scripture to conclude when Messiah will come. The sages said: “May the Spirit depart from those who calculate the end-time” (Sanhedrin Maimonides Introduction to Perek Helek 23 97b). One must believe that Messiah will have more station and honor than all the kings who ever lived, as all the prophets from Moses to Malachi prophesied: Whoever doubts this or minimizes it denies the passage begins, “You are standing”(Deut.29:9).A corollary of this principle is the assertion that the king of Israel must come only from the house of David and seed of Solomon. Anyone who rejects this family denies God and the words of His prophets.
 
The Thirteenth Fundamental Principle is the Resurrection of the Dead, which we have already explicated. 
 

This portion below was taken from an artcile by Daniel Septimus from the website www.myjewishlearning.com 

 

The following is largely based on Marc Shapiro’s "Maimonides’ Thirteen Principles: The Last Word in Jewish Theology?" published inThe Torah U-Madda Journal, volume 4 (1993).

Maimonides wrote his Thirteen Principles of Faith in his introduction to the tenth chapter of Talmud Sanhedrin.

 

According to Maimonides, anyone who denies–or even doubts–any of these principles is a heretic with no place in the World to Come. Yet, these principles were hardly undisputed. Many scholars who preceded and succeeded Maimonides held contrary beliefs.

Below, is a list of the Thirteen Principles with references to some of these divergent beliefs. Unless otherwise noted, all the scholars mentioned are medieval authorities.

The Principles

Principle 1

God exists; God is perfect in every way, eternal, and the cause of all that exists. All other beings depend upon God for their existence.

Objections

Some medieval authorities believed that God created the world from eternal matter (see Principle 4). Thus, according to these scholars, it would not be true to say that God is the cause of all that exists.

Principle 2

God has absolute and unparalleled unity.

Principle 3

God is incorporeal–without a body.

Objections

In the Mishneh Torah, Maimonides asserts that anyone who believes that God is corporeal is a heretic. In reference to this, Abraham ben David Posquieres (also known as Rabad) comments that people greater than Maimonides have believed that God has a physical form. Rabad himself does not subscribe to this view, but objects to the claim that those who do are heretics.

In addition, Moses ben Hasdai Taku, a tosafist (medieval commentator on the Talmud), believed that God could take a physical form. Finally, Samuel David Luzzatto, a 19th-century scholar, defended the idea that God has a body, claiming that an embodied God was the only God conceivable to most people.

Ironically, Maimonides himself seemed to share this view. In the Guide of the Perplexed (I, 46) he writes: "For the multitude perceive nothing other than bodies as having a firmly established existence and as being indubitably true."

Principle 4

God existed prior to all else. (In a later version of the Thirteen Principles, Maimonides included the notion that God created the world from nothing [creation ex nihilo].)

Objections

In his commentary to Genesis 1:1, Abraham Ibn Ezra suggests that the word bara (created) implies cutting or setting a boundary. Scholars such as Joseph Tov Elem and David Arama understood this to mean that Ibn Ezra believed that God sculpted the world from eternal matter. Gersonides also believed that the world was created from eternal matter.

Principle 5

God should be the only object of worship and praise. One should not appeal to intermediaries, but should pray directly to God.

Objections

Some of the selihot prayers–prayers of repentance recited on fast days and during the High Holy Days–and the third paragraph of the Shalom Aleichem hymn, sung prior to the Shabbat kiddush, are directed to angels. In addition, one of the Geonim–the leaders of Babylonian Jewry from the 7th to 11th centuries–defended the use of angels to intercede with God (Ozar ha-Geonim, Shabbat 4-6). He added that angels could sometimes fulfill the petitions of a prayer without consulting God.

Jacob Emden (1697-1776) is among some of the others who have approved of petitioning angels to intercede on ones behalf. Nissim Gerondi (Ran) maintained that there is one specific angel whom one may pray to.

Principle 6

Prophets and prophecy exist.

Principle 7

Moses was the greatest prophet who ever lived. No prophet who lived or will live could comprehend God more than Moses.

Objections

Nahmanides and Gersonides believed that the Messiah would gain more knowledge of God than Moses. Shneur Zalman of Lyady (1745-1813), the first Lubavitcher Rebbe, in his Likutei Amarim, notes that Moses’ prophetic abilities weren’t as great as those of Isaac Luria, the renowned medieval kabbalist.

Principle 8

The Torah is from heaven. The Torah we have today is the Torah that God gave to Moses at Sinai.

Comment

This principle assumes that there is and has always been one text of the Torah and that the Masoretic text–the text established by ben Asher in 930 CE–is this text.

Objections

The Talmud (Baba Batra 14b-15a; Makot 11a) relates that Joshua wrote the last 8 verses of the Torah. Abraham Ibn Ezra believed that Joshua wrote the last 12 verses. The Midrash Tanhuma, a rabbinc text, cites cases of tikkun soferim, instances where the scribes of the Great Assembly (the leaders of the Jews during the Persian exile) emended the Bible–including the Torah.

Menahem ben Solomon ha-Meiri mentions the "Masoretic works" instead of a singular "Masoretic text."

Solomon ben Aderet (Rashba) discussed when we should change our Torah to accord with the Talmud’s version (which differs from the Masoretic text). Aryeh Loeb Guenzberg (18th century) opined that the commandment that every Jew write a Torah scroll no longer applies because of our doubts about how certain words are to be written. Similarly, Moses Sofer (1762-1839) believed that there’s no need to say a blessing before writing a Torah because, perhaps, the Talmud’s version is correct and the Torah being written is invalid.

Principle 9

The Torah will never be abrogated, nothing will be added to it or subtracted from it; God will never give another Law.

Objections

Joseph Albo suggested that, in theory, if a prophet came whose mission could be verified in the same way Moses’ could, then commandments–except for the Ten Commandments–could be abolished.

Principle 10

God knows the actions of humans and is not neglectful of them.

Objections

According to Ibn Ezra, "The Whole [God] knows the individual in a general manner rather than in a detailed manner." Some interpreted this to mean that God knows the general actions of humans, but not the particular details. Gersonides developed this idea fully: God knows universals, but not particulars.

Principle 11

God rewards those who obey the commands of the Torah and punishes those who violate its prohibitions.

Principle 12

The days of the Messiah will come.

Objections

The talmudic Rabbi Hillel (not to be confused with the earlier Hillel) stated that: "There shall be no Messiah for Israel, because they have already enjoyed him in the days of Hezekiah (Sanhedrin 99a)."

Principle 13

The dead will be resurrected.

Conclusion

In Judaism, disagreement is not anomalous. However, whereas in the legal tradition we can speak of a mahloket l’shem shamayim–a debate in the name of heaven (God)–according to Maimonides, debate is not possible when it comes to dogmatic principles. The consequences of diverging from Maimonides’ principles are severe.

After listing and describing his Thirteen Principles, Maimonides states: "When all these foundations are perfectly understood and believed in by a person he enters the community of Israel and one is obligated to love and pity him…But if a man doubts any of these foundations, he leaves the community [of Israel], denies the fundamentals, and is called a sectarian, apikores, and one who ‘cuts among the plantings’ [a reference to the talmudic heretic Elisha ben Abuyah]. One is required to hate him and destroy him."

According to this assessment, revered authorities–such as Ibn Ezra, Nahmanides, Rabad, ha-Meiri–whose works are studied to this day, would fall into the latter category. They would be considered heretics who not only have no redemption in the afterlife, but who are not true members of Israel and who deserve nothing but our scorn.

What are we to conclude from this?

Probably not that these scholars were heretics, nor that Maimonides’ principles were incorrect or untrue (for in most cases, even the divergences from Maimonides were relatively minor). If we can conclude anything from this analysis, it is that the Thirteen Principles of Faith–as articulated–were never normative, never as defining and consequential as Maimonides believed them to be