In a book by Richard Dawkins, The God Delusion, the author uses various arguments to strongly attack the idea of any non-material intelligence existing outside of nature as being just a myth.
However, the belief in the existence some kind of intelligent Creator has been widespread among people though out human history. Even 70 years of cruelly enforced atheistic communism in the Soviet Union could not drive out this belief. Since the atheistic communists took over China, the Christian faith has exploded in that country.
So which is the delusion; God or atheism? The answer people give to that question depends on their presupposition. If you presume that the natural world is all that exists, then you can never prove God. However, if you presume that there is truth that isn’t based on the physical world, then the idea of God is obvious.
Since neither reason nor science can prove (or disprove) God, how can you know for sure — one way or the other? Think with me. If there is a Creator who could make the Universe and all that it contains, including humans with the capacity for communication, shouldn’t that Creator be able to directly communicate with the intelligent humans He has created?
So try this, don’t just blindly believe, but ask for communication. Sincerely say something like this: “If there is a creator, who or whatever you are, will you show me the truth about yourself.” Then listen and be open to communication. Don’t refuse it, block it, or explain it away by an anti-supernatural prejudice.
I was once an agnostic. I made a petition something like the one I just mentioned. A couple of years later I had a spiritual encounter that showed God to me beyond all doubt. Ever since that day, 41 years ago, God has been a constant companion, speaking to me, encouraging me, leading me, correcting me.
Nobody needs any proof that her/his own consciousness exists. You know that you have consciousness without rational proof. Does that make your consciousness a delusion? I don’t think so.