1 Peter 3:15 tells us to "always be prepared" to answer questions about our faith.
So let's consider the best way to answer this common question:
"Why push your beliefs on others? Just keep them to yourself and let others find their own truth."
"If you had the cure for cancer, would you keep it to yourself and watch someone die?"
"I'm sure you wouldn't."
"And since the Bible teaches that all who refuse to follow Christ will be condemned (Romans 8:1-8), and spend eternity in hell (e.g. Matthew 10:28), I would feel terrible to keep that information to myself."
"You don't need to agree with me about the Christian teaching of hell, but surely you see why I feel compelled to share Christ with others."
How would you answer this question?
Resources: In Revelation 21:7-8 Christ talks about Hell at his second coming. See also: There's No Away and Are There Many Ways to Heaven?