Cleo, you are going to go to hell.
Actually I prefer to fuck with their minds:
Method One: I mention something about homosexuality then when they tell me it is a sin I look confused and say "How come? because God is gay!" After they have calmed down enough to listen I use the bible to prove this fact.
Method Two: I tell them I won't listen to them because they are deliberately going against God's wishes. When they ask why, I point out that they are wearing clothes and then quote the passage in the bible that tells us that God wants humans to be naked at all times.
This is the advantage of being brought up Catholic, of going to a catholic school, and having religious education every week from the age of five to the age of sixteen (and for winning the "religious prize" at the age of 11). I know enough about the bible to be able to prove God wants you to do whatever stupid thing I can think up.
(For example: Did you know, according to the bible, if you regularly go to church on Sunday and hold that day to be God's day, God will, in return, torture your children and your grandchildren!)