"In the first book I will include all the commandments that are principles of the law of Moses and that a man should know before all else, such as the unity of Ha-Shem and the prohibitions related to idolatry. And I have called this book the Book of Knowledge."

1. The Foundations of the Torah - Yesodei Ha-Torah

a) G-d Exists

The basic principle on which all else depends is that G-d exists, as it says in the Torah "I am Ha-Shem your G-d".¹ There is no other god but Him, as it says "You shall have no other gods".^2,a

G-d is unique, as it says "Hear, O Israel: Ha-Shem is our G-d, Ha-Shem is one".^3,b He is not like any material thing, as it says "To whom would you compare Me that I should be equal?".⁴ He has no form, as it says "For you saw no image on the day that Ha-Shem spoke to you".⁵ He is everywhere, as it says "For Ha-Shem is G-d in the heavens above and on the earth below".^6,c When the Torah and the prophets speak of Him as though He were a person it is only by way of analogy and metaphor; regarding all of these things our sages said "The Torah spoke in the language of mankind".^7,d

b) Love of G-d and Awe of G-d

We must love G-d, as it says "And you shall love Ha-Shem your G-d"⁸; and we must also stand in awe of him, as it says "You shall fear Ha-Shem your G-d".⁹ If a man considers G-d's great and wonderful works and realizes His boundless wisdom he will yearn to know more about His greatness, as it says "My soul thirsts for G-d".¹⁰ But when he thinks about these things he will also realize his own lowliness, as it says "What is man, that You remember him?"^11,e

c) Sanctification of G-d's Name

We are commanded to sanctify G-d's Name, as it says "And I shall be sanctified among the children of Israel"¹²; and we are forbidden to desecrate it, as it says "And you shall not desecrate My holy name".^12,f If anyone deliberately disobeys a commandment of the Torah he desecrates the Name, while if he abstains from transgression or performs a commandment without ulterior motives he sanctifies the Name.^g

One may transgress a commandment in order to save one's life, as it says "That a man may perform them and live by them"¹³ -- "live by them, not die by them".¹⁴ But one must die rather than transgress the commandments against idolatry, fornication and murder, as it says "Love Ha-Shem your G-d with all your heart and with all your spirit"¹⁵ -- even if he takes away your spirit (i.e., your life).¹⁶ Moreover, if the intent is to force the Jewish people to violate a commandment or to force an individual to violate a commandment publicly, one should die rather than transgress any commandment. In all such cases if one dies without transgressing he has sanctified the Name, but if he transgresses he has desecrated the Name.^h

It is forbidden to destroy a sacred place or sacred writings or to erase the name of G-d, as it says "And you shall wipe out their name (i.e., the name of idolatry) from that place; [but] you shall not do so to Ha-Shem your G-d".^17,i Similarly, it is forbidden to think or speak about sacred things in improper surroundings such as places where there is excrement or where people are nude.^j

d) Prophecy and Revelation

It is a principle of religion that G-d reveals knowledge to prophets ^k: ["I will raise up a prophet from among them... and will put my words in his mouth and he will say to them everything that I command him"¹⁸]. If a man is known to be worthy of prophecy by virtue of his wisdom and his deeds, and if he performs signs (i.e., he foretells the future) and says that G-d sent him, we are commanded to obey him, as it says "Ha-Shem your G-d will raise up a prophet from among you... you shall listen to him".^19,l "And if a man does not listen to My words which he speaks in My name, I will settle with him".^20,m It is forbidden to doubt his prophecy and it is forbidden to test him excessively, as it says "Do not test Ha-Shem your G-d".^2l,n

The prophecy of Moses was greater than that of any other prophet^o [as it says "And no prophet like Moses ever again arose in Israel"²²]. The revelation at mount Sinai is the proof of the truth of his prophecy, as it says "I shall come to you in a thick cloud so that the people will hear Me speak to you and will also believe in you forever".²³ All Israel were witnesses that his prophecy was true.^p

The Torah is an eternal commandment not subject to changes or deletions or additions, as it says "Observe and perform all of what I command you; do not add to it and do not diminish it"²⁴; and it says "The things that are revealed belong to us and to our children forever so that we may carry out all the words of this Torah".²⁵ No prophet is allowed to make innovations; if he claims that G-d sent him to add a commandment or subtract a commandment, or to interpret a commandment in a way other than what we have received from Moses, or if he says that the commandments given to Israel are not eternal, he is a false prophet, for he has contradicted Moses' prophecy.^q

Sources:
1. Ex. 20:2, Deut. 5:6	a. 1:6
2. Ex. 20:3, Deut, 5:7	b. 1:7
3. Deut. 6:4	c. 1:8
4. Isaiah 40:25	d. 1:12
5. Deut. 4:15	e. 2:1-2
6. Deut. 4:39, Joshua 2:11	f. 5:1
7. Berachos 31b	g. 5:10
8. Deut. 6:5	h. 5:1-4,7
9. Deut. 6:13	i. 6:1,7
10. Psalms 42:3	j. See Kerias Shema 3:4-5
11. Psalms 8:5	k. 7:1
12. Lev. 22:32	l. 7:7, 10:1
13. Lev. 18:5	m. 9:2
14. Sanhedrin 74a	n. 10:5
15. Deut. 6:5	o. 7:6
16. Berachos 54a	p. 8:1-2
17. Deut. 12:3-4	q. 9:1
18. Deut. 18:18
19. Deut. 18:15
20. Deut. 18:19
21. Deut. 6:16
22. Deut. 34:10
23. Ex. 19:9
24. Deut. 13:1
25. Deut. 29:28