I believe that God reveals himself to all people that are mentally capable. Ravi Zacharias is the most solid Biblical teacher and philosopher I know of. He has had many encounters with Muslims that later came to Christ. One guy said he dreamed of Jesus every night for 7 years, and then finally understood what the dreams meant. Just as those of us raised in Christian homes who later doubt if anything is real, those raised in Muslim and Buddhist homes also reach an age where they have to ask themselves what is the real truth. If God was a beer drinking partier sitting on the clouds that let everyone in that wasn't a murderer, would that be a god you would worship? God is Holy and perfect, and worthy of worship. Who am I to question who he gives mercy to and who he gives justice to? I know that I am guilty, and if went before the holiness of God, I would be even more convicted of my own wickedness.
It is fantasy land to believe that every person who has ever lived has been exposed to Jesus at least once in there life.
So what if missionary workers go to 3rd world lands to preach the gospel.
That reduces the percentage of people who have never heard of Jesus from 100% to 98%.
I have no doubt that there are examples of people that live in some of the most ungodly places on Earth somehow found a way to have the word of God revealed to them.
But there have been billions of people who were born and died who never heard the word Jesus one single time in the history of there life.
I have a really hard time believing that those people are burning right now.
And lastly the Bible talks about people are only accountable for what they know.
This is my defense when it comes to my belief that if you never heard of Jesus you dont go to hell.
To whom much is given much is required.
Luke 12:48
But someone who does not know, and then does something wrong, will be punished only lightly. When someone has been given much, much will be required in return; and when someone has been entrusted with much, even more will be required.
That Bible clearly states you are only accountable for what you know.
Its all over the place.
Every single time the Bible talks about someone going to hell if they dont confess it was in a Christian setting.
It was either Jesus speaking to his disciples, or it was Paul speaking to the Church.
In both cases all the people being spoken to in those verses knew better, so they were accountable and those people those verses applied to.
A lot of sayings in the Bible you have to account for the setting and who was being spoken to.