If god was evident, should not everyone come to the conclusion that he exists?

Yes. Most atheists deny the existence of God because their lives are built around religion and religious people but don't want to accept religion. God exists without any form of religion. Science doesn't explain everything. There's still no evidence the big bang happened or what caused it if it did and if the scientists have to come up with theories, there has to be something more we definitely don't know about.