“Taking action is perhaps the wrong word, though, since what is most often necessary is deliberate inaction. For example, if every Christian in America who claimed to be pro-life would simply refuse to vote for any candidate—regardless of party—who supports abortion, the abortion laws would change within two election cycles.” –Joe Carter
This guide might come in handy!
http://thegospelcoalition.org/blogs/tgc/2013/05/03/how-to-change-a-society-in-5-easy-steps/
Examples of this dynamic here.