I was raised Catholic, and here is Catholicism in a nutshell:
1. Be Zealous
2. Be sure your religion is the only valid approach to spirituality in the universe, and insist that any other approach is stupid or blasphemous
3. Ignore science
4. Ignore logic
5. Be insecure, and use the idea of a christian God to smooth out the inconsistancies in yourself
6. Be very afraid of death, and quell that nagging fear with idea of being greeted with a paradise instead of nothingness
7. Feel guilty. All the time. Because humans are sinners who are always sinning and the only way you can be a good person is to pray to God to cleanse your sins so you can go out and sin in the exact same way again. As long as you keep going to church to reset the sin-count (and throw a few bucks in the collection plate of course).
I think there's some stuff about Jesus too.