I used to debate this question with my friends. I'd ask, "What if a man came along and he cured cancer and gave all his money to the poor? Would God really send him to hell because he didn't believe in Jesus?"
What answer do you think I got?
Let's work through this question and those similar. If someone is good, spends their life doing moral and ethically correct actions, will God send them to hell just because they didn't believe? First, let's talk about good actions. A person can do amazing things all day long but they are still a sinner. So if a man cured cancer, gave his money to the poor, ect., he'd still be a sinner. He still wouldn't be good enough to spend eternity with God. Why? Because God hates sin. He will not allow sin into Heaven. That's the bottom line.
But you may be saying that certain actions should out weigh small sin. So let's say our man who cures cancer doesn't have any "major" sin in his life. Let's say that he doesn't gamble, or get drunk, or do drugs. He doesn't cheat on his wife, he's never even killed an ant or spider. How about now? Surely a man like this can go to Heaven.
No. He can't. Because even though he doesn't do the "big" sins, his heart is most likely conflicted with some sort of sin.
Don't believe me? Try living sin free for a day and you'll see that it can't be done. At some point, you may feel jealous or greedy or vain. It's just the human condition. Even when we try our hardest, we can't be perfect.
So what's the point of trying? Well, we don't try to be perfect to go to Heaven. We model Christ's behavior because we love him. Think back to your teenage years. Did you ever ask your parents to buy you a certain type of t-shirt because all your friends had it? Or did you ever save up your money so you could have the same type of shoes your friends had? You wanted to be like them. Well, followers of Christ want to be like him so they follow his example. That's why we do good things. And no, we aren't perfect. We'll fail and sin everyday.
That's why Jesus is needed to go to Heaven. He took our sins away and without that sacrifice, no one would be allowed in Heaven.
What if the man who cures all cancer doesn't know about Jesus? What if no one ever preached to him about God? Then will he still go to hell? The Bible mentions this situation. It says that those who have never heard the Truth but live with it in their hearts will still go to Heaven. But if you hear the Truth and turn from it, you won't be allowed to live with God.
Now you might be thinking something like, "That's crazy harsh! What type of God would condemn people to hell?" Let me offer an alternative way to think about hell:
God doesn't condemn people to hell. We condemn ourselves.
We make the decision to love or not love Jesus. So it's up to us where we spend eternity.
If you're on the fence, I suggest prayer. I suggest praying to Jesus, "Lord, help me become a follower. Help open my heart so that I can love you." Start with that and keep at it.