God in Bible is not the only one. There are more like him. So he can't be the Supreme God

Bible Genesis

Holy Bible - Genesis

3:22 - Then the Lord God Said, " Now these humans have become like one of us and have knowledge of what is good and what is bad.

Point to Ponder

The Lord God is saying that after eating the fruit these human beings have become like one of us.

The key statement here is "one of us".

The God, who is saying this statement, is also referring to other Gods of equal status, that is why he is using the line "one of us" which means he is not alone. There are more like him.

Bible Genesis 18

Holy Bible - Genesis 18 - The Three Visitors

18:1 - The Lord appeared to Abraham near the great trees of Mamre while he was sitting at the entrance to his tent in the heat of the day.

18:2 - Abraham looked up and saw three men standing nearby. When he saw them, he hurried from the entrance of his tent to meet them and bowed low to the ground.

Up till 18:22 there is mention of 3 people. They are addressed in Bible as "they". This further proves that the God in Bible is not alone. There are more like him. Threfore he cannot be the Supreme God.