Grace is a universally provided force. We can consider, for instance, if it is the path of Jesus' life which is of the most value or Jesus himself.
Many in life do not get to even hear of him much less choose to follow, I do not believe there is anything in God's law that prevents someone from receiving the kingdom when they have done the very best based on what they know to be on a path which is much in line with what Jesus proposed for us, but which was not given them to follow by Jesus' teaching themselves specifically.
There is much we always do not know and any provisions we make about what will lead us to heaven we should make only for ourselves, for all others we pray for the extension of grace, because all of humanity can benefit from this force, as the evidence of suffering, ergo lack of grace, is indeed all around us.
Grace is a universal force because I believe the Holy Spirit runs all religions. Every religion has their final destination. I hope you're not assuming that I'm making Christianity as the best religion in the world. Grace is available. It's plastered on the internet. It's even on TV. It's everywhere. Do most people want it? What are they doing to find out more about it? Are they too busy with other delights? The sharing of my faith shines through because of my love for Jesus Christ. I'm sharing this good news because Jesus is all about love.
Matthew 7:7-12 and Revelation 3:20