A common "what if" question that people bring up is, "What if someone lived in a remote location and never heard the name of Jesus?" The accusation is that, if Jesus is the only way, then God is unjust for condemning anyone who has not heard of Jesus. Never-mind that the person making this accusation has heard of Jesus and is really implying that their moral standard is higher than God's.
While this specific question may not have been precisely addressed in the New Testament. Romans 1:18-20 states, "The wrath of God is being revealed from heaven against all the godlessness and wickedness of people, who suppress the truth by their wickedness, since what may be known about God is plain to them, because God has made it plain to them. For since the creation of the world God’s invisible qualities — his eternal power and divine nature — have been clearly seen, being understood from what has been made, so that people are without excuse." However, there are many other verses to consider to get a complete picture so we can learn the heart of God on this issue. Let us start with similar principles that we do know from the Bible for a more complete view on the subject:
1) We know that Jesus is the the only way to the Father (if there was any another possible way, then Jesus would not have had to die - Mark 14:35-36).
I Tim 2:2-6 ...live peaceful and quiet lives in all godliness and holiness. This is good, and pleases God our Savior, who wants all people to be saved and to come to a knowledge of the truth. For there is one God and one mediator between God and mankind, the man Christ Jesus, who gave himself as a ransom for all people.
2) We know that when Jesus was in the grave for three days, He preached to those who had died before, so that even the Old Testament prophets must go through Jesus to enter the Fathers presence because nobody (except Jesus)
is good enough on their own merit. We also know there are only two options when we die, one with Jesus and the Father and the other in complete separation from God.
I Peter 3:18-20
I Peter 4:5-6
3) We know that God has reached out to specific individuals in the New Testament who were honestly (see Jeremiah 17:9) seeking to serve Him and we also know that God does not show favoritism (Romans 2:11-16). There are also many missionaries who have witnessed people who had never heard of the Gospel, having dreams or visions that directed them to the missionaries. Today, there are people in places where Christianity is illegal (like Iran), who are having powerful dreams leading them out of Islam to Jesus with a great underground movement.
4) We know that God is righteous and Holy (Genesis 18:25 "Will not the Judge of all the earth do right?"). He loves us (John 3:16) and does not want any human being to end up in eternal punishment (Ezekiel 33:11 - "Tell them: As I live” — the declaration of the Lord God — “I take no pleasure in the death of the wicked, but rather that the wicked person should turn from his way and live. Repent, repent of your evil ways!"). However, He will not violate the free will He has given to us. His Holiness cannot allow sin to enter Heaven. If you do not want God's rule and His presence right now, He will not force you to join Him in Heaven.
II Peter 3:9
5) We know that we are instructed to spread the "Good News" to all the world (Acts 1:8). Knowing how much God loves us means that we must trust that His method offers the best possible chance to bring salvation to others. So now the "what if" becomes, what if you had responded to the "Good News" and then you shared the "Good News" with others, who took the "Good News" to others, who reached out to that person you are so concerned for who has never heard the Gospel? What if your failure to respond to the Gospel has a chain-reaction effect that eternally impacts your family, friends and many others? Will you be held accountable for all those that you failed to share the Gospel with? Luke 12:48 - "Much will be required of everyone who has been given much. And even more will be expected of the one who has been entrusted with more." You do not want to be the one who buried the "talent" (Matt 25:14-30) or the one who refused to put on the garments (of righteousness) that were offered (Matthew 22:1-14).
6) We know that sadly most will reject God's "Good News" offer, choosing the proud and selfish path to eternal destruction (The Bible is clear, there is no reincarnation - Hebrews 9:27 - Just as people are destined to die once, and after that to face judgment,).
7) We know that God does not discriminate as He will have people from every nation, tribe and tongue that will follow Jesus (the real question is, will you and your loved ones be included?).
This is where faith (trust) in God's character is required for issues we do not fully understand (Isaiah 55:9). In Hebrews 11:6 we learn, "And without faith it is impossible to please God, because anyone who comes to Him must believe that He exists and that He rewards those who earnestly seek Him." Whenever someone thinks they have God trapped in their box and that they have outsmarted God, whether they realize it or not, they are joining those who have rebelled against God. That is exactly what Satan thought when he deceived Eve and Adam. Look at the New Testament verses where the Sadducees, Pharisees and Scribes tried to trap Jesus with difficult questions and see how that worked out for them. If we could understand all that is going on in the heavenly realm and could see the big picture, we would look at this temporal life differently. We would understand why it took 21 days for Daniel's prayer to get through the spiritual warfare that was in progress in the heavenly realm (Daniel 10:13). We would grasp that none of us can stand before The Almighty as we all have a sin problem and need a Savior. The philosopher Socrates understood this problem and 500 years before Jesus. He mused, "It may be that the Deity can forgive sins, but I do not see how." We are told that this heavenly conflict is temporary and the restoration of all things will happen at the end of time when sin, evil and death are cast into the eternal lake of fire (Rev 20:14). In this life, we see as "through a glass darkly" (1 Corinthians 13:12) and need to trust the One who made the universe and knows the future, who is also the only One who can save us from our sins.
I think it would be very foolish to question the Creator of all life or His judgments, without having the benefit of knowing all of the eternal ramifications.
Proverbs 14:12 "There is a way that appears to be right, but in the end it leads to death."
Isaiah 29:16 - "You turn things upside down, as if the potter were thought to be like the clay! Shall what is formed say to the one who formed it, "You did not make me"? Can the pot say to the potter, "You know nothing"?
Isaiah 55:8-9 - “For my thoughts are not your thoughts, neither are your ways my ways,” declares the Lord. “As the heavens are higher than the earth, so are my ways higher than your ways and my thoughts than your thoughts."
Ecclesiastes 3:11 "He has made everything appropriate in its time. He has also put eternity in their hearts, but man cannot discover the work God has done from beginning to end."
1 Corinthians 2:14 - "But the natural man does not receive the things of the Spirit of God, for they are foolishness to him; nor can he know them, because they are spiritually discerned."
As a Christian, I know this present world is currently under control of "the deceiver" for a limited time. The "Father of lies" has one goal, to turn everyone away from the only path to eternal life, through Jesus. Creating doubt and misquoting the scriptures is one of Satan's main methods of attack. The evil one does not care which of the false religions or anti-Biblical worldviews lures you away from the Truth. Therefore, I will trust in God's character as He reveals it in His Word and also in His knowledge of all things, to make what is ultimately the most righteous decisions.