You don't base religious or life beliefs around evolution. You base absence of them around evolution. There is no such thing as failing in the biological sense. "Failing" to produce offspring implies that you are either physically, mentally, or environmentally unable to reproduce. It can only help the gene pool. And failure to believe that you and everything else are a product of one invisible, all knowing omnipotent being that is perfect in every way is not pessimism. It's only pessimistic compared to primitive delusions of grandeur that in many cases can be traced back to the use of hallucinogenic drugs used during the stone age to create "spiritual trances" meant to complete a hunt in the "dream world" and thus ensure it's success in the "real" world.
