3. Acknowledging God's Existence

Yesodei HaTorah 1:5

This One Who created everything is Hashem, the God of the universe. He controls everything with unlimited and uninterrupted power, keeping the universe constantly in motion. God keeps everything moving without having to exert any physical force whatsoever.

Yesodei HaTorah 1:6

There is a Torah obligation to know that God exists. Exodus 20:2 (one of the “Ten Commandments”) says, “I am Hashem, your God...." (which is a requirement to be aware that He exists). Thinking that there is another “god” violates a Torah prohibition, as per Exodus 20:3, "You shall have no other gods in My presence" (which is everywhere). Imagining such a thing denies a fundamental principle upon which Judaism relies.