In the gospel message, we are told to believe Jesus, and to respond to his promise to save us from punishment for our sins. We are told that failure to respond to Jesus, and refusing to believe him results in our being separated from God . However, that is kind of inside out. We are all separated from God and on our way to eternal death and eternal separation from God, until we respond to Jesus in belief and repentance from our sin. In other words, on the spiritual Titanic, some of us are offered a lifeboat. Some refuse the lifeboat because they disbelieve the danger or don’t want to leave the cushy cruise ship. They will perish. Then, there are those who aren’t offered a lifeboat at all–I guess those are the ones you would say “haven’t heard”. What happens? We simply aren’t told. We do know God and Jesus never condemn those who are ignorant, only those who willfully refuse to believe Jesus or respond to him. Jesus knows the condition of every heart. Look at the book of Romans chapter3:21-31, and all of chapter 4. We are saved through faith. It means we believe what God reveals to us, even if it isn’t the whole picture. Abraham believed God and it saved him–even though Abraham had never heard of the gospel or of Jesus Christ. Those who never heard the gospel, yet respond in faith to the light they are given have that faith in God credited to them as righteousness. Who knows what God reveals to hearts in the last moments of life? Who knows how God does anything that has not been revealed to us? What has been revealed is that salvation comes from responding to God/Jesus in faith. Perhaps the biggest worry is for those who have heard the gospel and know about Jesus yet push it away as unimportant to their own plans. I hope this helps you, and helps those who ask you this question about “those who haven’t heard.”
Who is Jesus for you? Where are you on your journey with him? Faith is more than a one time decision to believe. It is a lifelong trust in his guidance, and willingness to follow where he leads.