It's not a delusion. It's called the happiness advantage and it's real. Performance is 33% better when in a happy state than when in a neutral, negative or stressed state. You can literally train your mind in thirty days to naturally be in a happy state. All things Christian do as part of the practice of their faith. Turns on all the learning centers of the mind.your delusion is for you a way of life, the same as believing a false religion is an advantage to the one that does exist for belief in itself offers an advantage regardless its authenticity is all that is necessary. exactly why you are a christian, your personal well being than the path set by the true heavenly religion of antiquity.
as all other species understand, the paradisian path to have evolved equally or greater than humanity or that all humanity does not follow the same religious doctrines. or any at all.
So it makes perfect sense that religion has a functional advantage over no religion and has continued to exist, in overwhelming numbers, in every society since the beginning of man. Does it matter which religion one practices to achieve the happiness advantage? No. It's all about the process of placing the mind in a happy and thankful state.