There is a infamous man on YouTube called the "TheAmazingAtheist". Follow his teachings as he will guide you toward Enlightenment. For the time of Cleansing is almost here. Greet the new day, young one. Your parents must accept your non-existent beliefs or the Lord shall cast upon them a terrible treachery of immortality in Paradise.

Or you could tell them you are gay They will probably cry. Then, in a few weeks, tell them that you are only joking and say that you are only an atheist. They will be so full of joy that they wouldn't care! Profit!