I'm a born again Christian and I've run into this grey area myself. as humans we can't possible know the answer, only God himself can look at the hearts and lives of each individual person and judge them accordingly. God judges the heart for purity, humility, and other like factors. There's no way he'll just make a decision that all good people who never knew him should go to heaven or hell.
But I will offer this, in John 14;6 Jesus says "I am the way, the truth, and the life: no man comes unto the Father, but by me." The father is in heaven.
In order to go to heaven, one must be living in the light of God. Otherwise, they're still living in darkness (not knowing God). Living in darkness leaves one susceptible to sin and although everyone sins, only those who pray for forgiveness are forgiven. People can pray for the forgiveness of other people as well.
There was a murderer who died on a cross with Jesus. His life close to death, he opened his heart to Jesus and repented. The murderer did not necessarily love Jesus, but Jesus knew that in his heart, he was genuinely remorseful for his sins and so he's in in heaven with him now.
Point: I want to say that with out the love of Jesus in you, you go to hell regardless of how good you were on earth, but then again, God judges the heart and looks back on the things you did while living. The only one that can make that decision is the creator himself.