WILL EVERYONE HEAR THE GOSPEL BEFORE THEY DIE?
This is a very brief answer to the question: 'Will everyone hear the gospel before they die?'
Revelation 5:9 indicates that people 'from every tribe and language and people and nation' will be saved. This does not mean that every single individual person who ever lives will have had the opportunity to hear the gospel of Jesus Christ. What it does mean is that the Gospel of Jesus Christ will be taken to every tribe, language, people and nation before the end comes, and that some people from every one of those tribes, languages, people groups and nations will be saved.
This is affirmed by Jesus in Matthew 24:14 which states that 'this gospel of the kingdom will be preached in the whole world as a testimony to all nations, and then the end will come.'
But there is a revelation of God that is universal - a revelation that every human being is confronted with every day of their lives, and that challenges everyone to believe in God, and leaves everyone without any excuse for unbelief - God's self-revelation in creation, in the things that he has made. Read Romans 1:18-20 and Psalm 19:1-4.
Because, as Romans 1:18-32 strongly teaches, we have all rejected, corrupted or distorted this revelation of God which freely available to us through creation, in order to be saved we must first hear then believe the good news of Jesus Christ [Romans 10:8-15]. This puts the clear responsibility on everyone who has heard and believed to pass that good news on to others, so that they also will hear and have the opportunity to believe.