Custardo, THANK YOU for asking this question. My massive faith crisis as a teenager was started when I wondered exactly what you are wondering - and was slapped down by nuns at catechism saying "Don't ask questions, just pray" / "The unbaptised don't deserve God's mercy" / "If you don't believe Jesus' words you are already condemned". Seriously. And, sorry if I cause offence, the intransigence of a few of the answers here remind me of what those nuns said. Shudder.
Anyway, having slowly and painfully regained some kind of faith (should that have a capital F?) I am still stuck with the original question. Here's the answer I've reached so far
:
A) Jesus definitely said "I am the way, I am the truth, no one comes to the Father unless they come through Me"
B) Jesus also very clearly said that we will all be judged by how much (or little) we treated every other person we met as if they were Jesus Himself - "I was hungry and you did not feed me" etc.
C) So, it seems to me that Christ wanted us all (all humans, pharisees samaritans sinners hindus whoever, if it is true that God sent His only Son to save all humanity as opposed to a few WASP bigots) to see Him in each other. Meaning that we have to look deep into every person, past their flaws and the treetrunks in our own eyes, and find what there is to love in them. And love them. As if there was Christ in them, as if they were Jesus.
D) So could it be that if any human, of whatever age / era / place / religion, manages to attain that state whereby they see God's Love in other humans - could it be that they know the Father (=God of love and peace?).
Buddhists would call that Nirvana, Sufis would call it losing themselves to enter God's Love.
I hope that makes sense. I am still bothered by the OP's question; also by the many questions prompted by my own answer to it. Will follow this thread with interest.
Mental capacity exhausted by posting this, about to stagger off to bed!