Copied from: Debunking Christianity
Let me start out with biblical/ministry related ones and move on to others:
1) Become a Pastor. Then you’ll learn how church people really behave. It could sour you from thinking there is an inward presence of the Holy Spirit in the lives of Christians. Think Dan Barker, Charles Templeton, Joe Holman, yours truly, and many others. I had to start out this way. 😉
2) Become a Psychiatrist/Psychologist. Most practitioners in these fields do not believe. It’s probably because they know what makes people tick so they just can’t believe in a wrathful god who will judge us for our behavior or thinking patterns. Think Valerie Tarico.
3) Become a Biblical Scholar. I dare you. Do not stay within the confines of conservative scholarship, which is not much better than special pleading. Study at real schools. Think Hector Avalos (OT), Bart Ehrman and Bob Price (NT).
4) Become a Biblical Archaeologist. Just think William Dever and his books What Did the Biblical Writers Know and When Did They Know It?, Who Were the Early Israelites and Where Did They Come From?, and Did God Have a Wife?
5) Become an Anthropologist. Not only are most anthropologists non-believers they are also relativists. Think David Eller (my favorite).
6) Become a Biologist. Try to maintain intelligent design as a biologist. And after getting your degree try publishing a peer-reviewed paper defending it. Only one has ever slipped through the cracks.
7) Become a Neurologist. Once you see how the brain works it accounts for why we think and behave as we do without the god-hypothesis.
8) Become a Physicist. Enough said. Think Victor Stenger.
9) Become a Zoologist. Study animals and see how much they are like us, and how we are like them. You’ll be forced to consider their fate when they die compared to where humans go when we die. You’ll be forced to consider why they suffer so much if there is a good god.
10) Become a Cosmologist. The existing universe and the many other possible existing ones put out the fires of religious passion. You’ll be forced to consider the vastness of existence and the wastefulness of a creator god whose greatest creation is on this pale blue dot.
Be sure to also read the Top Seven Ways Christianity is Debunked By the Sciences.