There is only one real God. The complexity of the universe shows that if there were two or more, they would have to be acting as one, just to make things work.

Many people know God in their hearts. Many religions talk about the true God. The Christian religion (not necessarily the Christians who belong to the Christian religion) is the only religion that speaks about God accurately, even though many other religions understand some things about him accurately.

For example. The atheism religion has people who try to (unknowingly) set themselves up as God by proclaiming (falsely) that God doesn't exist. So, when they try to set themselves up as God, they proclaim that He exists. In addition, many of them understand certain factual science. They understand part of what God created. So, even they have some minor accuracy in their religion.