Why is atheism so much more enlightening and liberating than religion?

I don't think one is more enlightening or liberating than the other it just depends on what you believe in and even how you where raised. I know atheist who have become Christians and feel that they are now enlightened and I have friends that where Christan's and feel that they have been liberated by becoming atheist. I personally believe that human beings don't have the capacity to truly understand what is or isn't reality and I am happy with that conclusion.