if it meant that ten others destined for everlasting torment could be granted a place in heaven?
Let's say that these ten are some of the most selfless, moral, charitable people on earth - they just happened not to choose Jesus as their saviour. Perhaps they are atheists, hindus, devout muslims, whatever - they have all heard the Christian message and rejected it for one reason or another.
Part of me wants to echo what Iano already said, and part of me thinks by my own sacrifice, God might honor it. The act of goodwill might be exactly the kind of sacrifice God looks for.
Regardless, if the Scriptures are true, then I can't usurp the decision they've already made. So even supposing I wanted to there is no way for me to know if it would be honored anyhow.
“There is something which unites magic and applied science while separating both from the 'wisdom' of earlier ages. For the wise men of old the cardinal problem had been how to conform the soul to objective reality, and the solution had been knowledge, self-discipline, and virtue. For magic and applied science alike the problem is how to subdue reality to the wishes of men: the solution is a technique; and both, in the practice of this technique, are ready to do things hitherto regarded as disgusting and impious" -C.S. Lewis