and yet the bible mentions other gods. did the birth of jesus make those gods cease to exist?
Exodus 12:12
And against all the gods of Egypt I will execute judgment.
Exodus 20:3, 5
Thou shalt have no other gods before me. ... Thou shalt not bow down thyself to them, nor serve them.
Exodus 23:13
Make no mention of the name of other gods, neither let it be heard out of thy mouth.
Numbers 33:4
Upon their gods also the LORD executed judgments.
Deuteronomy 6:14-15
Ye shall not go after other gods, of the gods of the people which are round about you;(For the LORD thy God is a jealous God among you)
Joshua 24:2
They served other gods.
Judges 11:24
Wilt not thou possess that which Chemosh thy god giveth thee to possess?
Psalm 86:8
Among the gods there is none like unto thee, O Lord.
How many gods are there?
edit:
you say,
"a thing can't be both X and not-X at the same time." ok, then which is it? either there is only one god, as stated in the bible, or there are many gods, as stated in the bible.