I have many scientist friends who are evangelical Christians - indeed, I was still just about one myself when I first arrived at EvC. None of them doubt evolution for a second. But each has their own way of shoe-horning standard evangelical doctrine into the obvious physical nature of the Universe, and I would say that it is a bit of a juggling act to reconcile the two without slipping into more liberal theology. The common way of dealing with this is pure cognitive dissonance - simply partition your thinking.