The pro-life cause is increasingly viewed as a ‘religious thing’ (marginalize your opponent — great tactic!), but you don’t have to believe in anything supernatural to be against unnecessary human death.
Click here for links to a wide variety of pro-life resources and groups, only a few of which are religiously affiliated. (Thanks to Secular Pro-Life).
One of my favorites is Feminists for Life. Read FFL president Serrin Foster’s article “The Feminist Case Against Abortion” for an eloquent explanation of the group’s mission, motivation and heritage.