God Told Me So

How often have we heard (or even said) "God told me so" or "God told me to..."? I dislike that phrase a lot people I have found people use it frivolously and without God actually telling them anything. It's amazing how our desires quickly become what "God wants..."

There is a new book, entitled God Made Me Do It, addressing the absurdity of many people's claims of God's assertions. There is an associated site about people's tweets about what God has commanded.

I think it's hilarious and can be a good way to remind us of truth. Although I could see some others thinking it's heretical and blasphemous. What do you think? What's the line between humor and heresy?