How can I deal with this nicely?

Well, first off, no one will ever do anything for God because they are taking the checklist approach. What I mean by that is your father, should not be telling you what to do and how to get right with God. Now, I have been going to church my whole life, but I still was into drugs and stealing and things like that. It took the love of God to change. I didn't want to do anything anyone told me to and I dont serve God just because the Bible says. I only serve God because he served me first, personally in my life. Now as to what to do about your father, I would talk to him about shoving his beliefs down your throat and if he is a Christian that love like Jesus loved and be slow to anger like Jesus did.