Those who are so concerned with "what about those who haven't heard" start with a skewed view of God. They assume that
1) God is unable to reveal Himself without man doing it for Him.
2) God will be unjust during the judgment day.
3) God sets unfair expectations.
The Bible reveals that God has clearly revealed Himself in nature (Romans 1:20) in the hearts of people (Ecclesiastes 3:11) and the individual seeker (Deuteronomy 4:29) as it proclaims,
“But if from there you seek the LORD your God, you will find him if you look for him with all your heart and with all your soul.”
These scriptures prove assumption #1 as false.
Those who assume the above have come to their own conclusions about God--not based on truth. They are not speaking about the living God revealed in scripture, but rather an idol crafted out of their own politically correct imaginations. We see the correct view of God as stated by Abraham in Genesis 18:25...
"Shall not the Judge of all the earth do right?”
God will not judge us by which religion we associate with, nor what church we attend. God will judge according to the individual heart, and that heart will be judged by the measure of how much revelation was imparted to them.
If you do not believe the Bible, you have no argument because, according to your own philosophy, there is no god, no heaven, no hell, and no impending judgment. To argue would be just being contentious. However, if you DO believe the Bible, then you can also take the following as a promise.
Psalm 19:9
The judgments of YHWH are true and righteous altogether.
