It's a shame people take this so lightly. Some of the reply's to the OP are just plain mockery. Here you have someone legitimately laying out their delima, and you have nothing more constructive to add than "ShhhHHHH! Let them have their fun." or "Then you should have won the Scrabble game." If you have nothing constructive to contribute, than be an onlooker. Don't tack on your useless drivel of a comment, just because the topic makes you uncomfortable.
To the OP, I'm really sorry to hear that situation is one you (or a friend) is afflicted with. The truth of the matter is that professing with your mouth, and believing in your heart that Jesus is Lord, is the only way to heaven. Jesus said "I am the way, the truth, and the life, none shall reach the father (being God) accept through me. We were never told that this life would be easy, that's a common misconception. In fact, he tells us that as our relationship with him grows deeper, the more persecution will befall us. That's in part to do with the spiritual warfare going on around us everyday, and in part because of the sinful world we live in (and the sinful people that live in it).
Take this as an opportunity to witness to your parents, and use the support of your neighbors that are around you to keep you strong. I know it's easy to say something like that, when I'm not in your shoes, but believe me, we all face trials and tribulations, it's how we handle them that produce character and faith.
A good verse for you to learn and carry with you may be from the book of James Chapter 1 verses 2-3 "Consider it pure joy my brothers, when you face trials of many kinds. Because you know that the testing of your faith develops perseverance."
We are given free will to choose. God is a fair and just and almighty God. Trust that he loves you. You cannot get to heaven by works (being a good person). Read your Bible daily and spend as much time as you can with your neighbors that support you. Pray for wisdom and strength, and God will reveal to you the way to reach your parents. Don't despair, you'd be surprised at how the Lord can work in peoples lives, and just when you least expect it, something miraculous will happen in your life/situations. Bless you, and I'll remember to pray for you.