Evolution and Christianity don't have to be mutually exclusive. Someone could believe in God and evolution with the assumption that God designed the universe to allow for such natural processes to develop over time. As far as the thought of "why don't people just believe in Christianity so they don't go to hell", that's an argument known as Pascal's Wager. Personally, I'm not trying to make you think anything, I just want you to ask your own questions instead of accepting what you're told. If you want to look for reassurances and strength in your beliefs, do more than read the Holy Bible...
I actually have been, maybe not as much as I should have. But, half of what I am taught in philosophy. We would call it Bible class, but because when people transfer to a different school, we do not want to make any problems with non christian schools. Origionally, it was always what I was told. I was only a kid, I wasnt able to understand anything other than what I was taught. I have began to believe different than what I've been taught. I think I may have said this before, but I do believe in theistic evolutionists. Christians, that believe that God used evolution to create the world. Just like it was stated above.