Is there a specific command to not equate yourself to God? For instance, someone says, "I am God." This someone is a believer and a member of the Jewish faith, not an unbeliever. I'm curious if Moses addressed this at all.
The great Torah scholar and codifier of Jewish law, the Rambam (R Moshe ben Maimon, 1135-1204) compiled what he calls the "Thirteen Fundamental Principles of the Jewish faith", as derived from the Torah. They were to him "the fundamental truths of our religion and its very foundations." (from here).
Some have challenged to what extent everyone always agreed with all of them, but to a large extent they represent the foundational beliefs of every traditional Jew.
The first four principles are
Belief in the existence of the Creator, who is perfect in every manner of existence and is the primary cause of all that exists
The belief in God's absolute and unparalleled unity
The belief in God's non-corporeality, nor that He will be affected by any physical occurrences, such as movement, or rest, or dwelling
The belief in God's eternity
These principles are completely and fundamentally opposed to the idea that any man could be God. As such any person claiming to be God could not be called a believing Jew in the traditional sense.