For most Christians this is a no-brainer, but I believe it IS possible for a non-Christian to get into heaven.
First, I'm against that "you just have to be a good person" mentality. That is obviously contradictory to Christianity, as it is very evident in the Christian faith that there is no one who is good. It is also observable by the human nature, as we see how greedy people are and how even the nicest people can fall and commit atrocities. No one is innocent. It is NOT how good we are or what we have done, because we can never be good enough. This is a core concept of Christianity that is ignored even by many Christians.
The standard by which people get into heaven is not being weighed at a scale and found to be good based on a minimum score. The standard to get into heaven is absolute perfection, which no-one but Jesus Christ himself was able to achieve.
So, no-one can get into Heaven except through Jesus. Believing in Him is the only safe choice, and we also see many references in the Bible which support that.
We also see evidence in the Bible pointing out that there is some sort of conditional judgement (without saying that morality is relative, because it IS absolute). For example, the towns contemporary to Jesus would not believe in Him, despite all the evidence before their eyes. Jesus then says that he will be harsher on them during the day of Judgement than Sodom and Gomorrah.
We also know that God is merciful and just. He is also all-knowing, and he can know a persons true heart. He also knows the precise answer to all what-ifs: what if he was born in a Christian home, what if he never met person X, et cetera.
What I'm saying is that it is ultimately God's decision, and though truly believing in the divinity of Christ and accepting Him as a saviour ensures a place in Heaven, Jesus might choose to save many of those we consider to be lost - and maybe even reject many people we THINK are saved.
Ahh, the age-old argument. While I can only speak as a Catholic, and therefore cannot vouch for other religions, I shall do my best to illuminate.
God created all people with the intention that they will one day join him in heaven. That was the original intent of Adam and Eve. Their time on Earth would allow them to grow closer to God. Thus, sin messed it up, and all humans, regardless of religious affiliation, became subject to sin.
As a Catholic, I believe that salvation comes from faith AND good works. Belief does not guarantee entrance into heaven if you cannot "walk the walk," so to speak. Not to mention that all people spend time in purgatory in purification before uniting with God again (except the saints, but they're special). Maybe atheists and the such will have a longer time in purgatory. Who knows?
This brings me to my last point. Nobody knows what happens during and after death except God, if you believe in him. I believe that a person can convert and repent in the final moments, and God will accept them. I also believe that God, as an omnipotent being, can do whatever he pleases and take whomever he deems worthy, regardless of religion, into heaven if he so chooses. Therefore, your argument is moot. While God is a judge, he is a merciful one.
I am a Christian; I believe in God and I believe in heaven. I believe that as long as you don't commit sins like Hitler and Stalin did, or another type of major sin, then you will get into heaven. I can't see God sending people to burn forever just because they haven't spent their life believing in something that is amazing, and is understandable that you wouldn't believe in it.
I believe that there are different parts of heaven. Parts that are for the people who could not have been better Christians, where it is the nicest place ever. But I also think that there are places that are more 'normal'. This place, I believe, is where the people who have committed theft, etc. go.
Of course, my beliefs may change in the future, just like they have done in the past few years. I'm interested to see what you think. Will atheists get into heaven? What does it take to be sent to hell?
"For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life." John 3:16
If you believe in God you shall enter the gates of heaven. I am a Protestant. I was taught the ABCs of Salvation. A stands for Accept Jesus a you Lord and Savior. B, Believe Jesus that Jesus died on the cross for your sins and finally C, Confess your faith (sins). No matter the sin you committed, from a small white lie to a robbery you still have to ask for forgiveness. Anyone can do the ABCs of salvation. If you don't believe in Jesus, the son of God, you won't be able to go to heaven.