I feel one of the most important "causes" for Christians today is to stand against abortion. As such, it is particularly helpful to have really good resources for training. Here are some pages and audio clips to help:
Three Audio Lectures
A ton of resources from Life Training Institute
An article by Greg Koukl
Alan Shlemon Debate about abortion
Considering the fact that over 150 babies were killed during the 3-4 minutes I wrote this post (120,000 babies a day), I think the legalization of abortion is one of the worlds greatest evils today. It does not take long to train yourself to be able to make a difference. One human life is worth more than all the atoms in the universe, and we need to treat them as such.