It is clear in the bible that there is only one true God. Many Non-Christian false religions spread false doctrines about various gods. Let's read Isaiah 44:6, as it says "Thus saith the LORD the King of Israel, and his redeemer the LORD of hosts; I am the first, and I am the last; and beside me there is no God."
Isaiah is full of scriptures in which the LORD clearly states that He is the only true God. Here are a few scriptures that state that fact: Deuteronomy 6:4, Isaiah 45:22,Jeremiah 10:10, James 2:19, 1 John 5:20.
We must only worship the TRUE God!