Based on the Thirteen Principles of Faith formulated by the Rambam in his Commentary on the Mishnah (tractate Sanhedrin 10:1).
1. I believe with complete faith that the Creator, blessed be His name, is the Creator and Guide of all the created beings, and that He alone has made, does make, and will make all things.
2. I believe with complete faith that the Creator, blessed be His name, is One and Alone; that there is no oneness in any way like Him; and that He alone is our G-d - was, is and will be.
3. I believe with complete faith that the Creator, blessed be His name, is incorporeal; that He is free from all anthropomorphic properties; and that He has no likeness at all.
4. I believe with complete faith that the Creator, blessed be His name, is the first and the last.
5. I believe with complete faith that the Creator, blessed be His name, is the only one to whom it is proper to pray, and that it is inappropriate to pray to anyone else.
6. I believe with complete faith that all the words of the Prophets are true.
7. I believe with complete faith that the prophecy of Moses our teacher, peace unto him, was true; and that he was the father of the prophets, both of those who preceded and of those who followed him.
8. I believe with complete faith that the whole Torah which we now possess was given to Moses, our teacher, peace unto him.
9. I believe with complete faith that this Torah will not be changed, and that there will be no other Torah given by the Creator, blessed be His name.
10. I believe with complete faith that the Creator, blessed be His name, knows all the deeds and thoughts of human beings, as it is said, "It is He who fashions the hearts of them all, He who perceives all their actions." (Psalms 33:15).
11. I believe with complete faith that the Creator, blessed be His name, rewards those who observe His commandments, and punishes those who transgress His commandments.
12. I believe with complete faith in the coming of Moshiach, and although he may tarry, nevertheless, I wait every day for him to come.
13. I believe with complete faith that there will be resurrection of the dead at the time when it will be the will of the Creator, blessed be His name and exalted be His remembrance forever and ever.
The foundation of all foundations [and basic principles of the Torah] and the pillar of all wisdoms is to know that there is a First Being Who brings every existing thing into being. All existing things – in heaven, on earth and what is between them – come into being only from His true existence.
If it should enter one's mind that He does not exist – no other thing could have any existence. 
Mishneh Torah, Yesodei HaTorah, 1:1-2
