In the beginning God created the heavens and the earth. (Genesis 1:1)
The word used for God in Hebrew is (Elohim אֱלֹהִ֑ים), Elohim is plural the im is a suffix added to the end of Eloh (God). Elohim could also mean plural for respect, for example a King would refer to himself as we, a Royal we a majestic title given to himself. Now trinitarians often use Genesis 1:1 to prove God is not one, they claim Elohim is not singular rather it's plural making the verse speak of more then one God. They dismiss the idea that God was using the Royal we to refer to himself, and that other divine beings were working side by side with God, thus they come to the conclusion of trinity.
This is a very weak claim, since the verse doesn't show any sign of other divine beings working side by side with God. Throughout history Jews understood this passage as speaking of one God and not triune. If Trinitarians believe this verse speaks of trinity or triune God, then they will have to explain this verse from the bible.
"I said, 'You are "gods"; you are all sons of the Most High.' (Psalm 82:6)
This verse uses the same Hebrew word Elohim אֱלֹהִ֑ים), as found in Genesis 1:1. Note Jesus also quoted from psalm, which means he was well aware the Jews were called Elohim. Shall we conclude from this that Genesis 1:1 was speaking of God and the Jews creating the heaven and the earth together? Wouldn't this make more sense, since the exact same word (Elohim אֱלֹהִ֑ים) is used.
The problem trinitarians fall into is nowhere does Genesis 1:1 speak of three persons or divine beings. Trinitarians have to explain if Elohim means more then one, then was Genesis 1:1 speaking of God and the Jews working side by side, since the exact same word Elohim אֱלֹהִ֑ים) is used for Jews. The Jews being co workers with God side by side would make more sense, then saying three divine being did.