This is often a question that can be very difficult to comprehend. What if no-one speaks the language of a distant culture and no-one in that culture is able to read?
Allow me to share a true story with you. Back in the 1800’s a missionary Marcus Whitman and his wife Narcissa headed out west from New York and established a Mission in Oregon Country to convert lost souls and primarily Native Americans from the Cayuse Tribe. While there, natives were taught about Jesus and while communication was difficult, some progress was made. The longer the mission was established, communication increased and additional settlers made the journey to the Mission.
With new settlers in the area, European diseases were brought to the Cayuse tribe and many of the native children were unable to survive a measles epidemic. The Cayuse Indians not knowing that the missionaries had a natural immunity to measles, were convinced the missionaries were not caring enough for their children.
After this and additional disputes, the Cayuse then revolted and attacked the mission, killing many of its inhabitants.
A few years later, with the matter never being totally resolved, other settlers in the area petitioned to the Governor that the responsible Indians of the Cayuse tribe surrender. Tribal Chief leader Tiloukaikt of the Cayuse failed to surrender and a war broke out among the natives and the army. Eventually Tiloukaikt lost more of his own people in the ensuing war than were lost in the massacre.
Chief Tiloukaikt and a few others, not being thought of those who would surrender, actually did so and consented to stand trial for the actions that had been committed. He was sentenced to death and someone asked why he surrendered. He said “Did not your missionaries teach us that Christ died to save his people? So we die to save our people.”
I have no doubt they heard the good news, as evidenced in the response of the chief, however they rejected it and were filled with violence.
It would be unjust if people went to hell without ever having any opportunity to know God. But the Bible explains that everyone does have the evidence and opportunity to call out to the one true God.
Romans 1:18-19 states:
18 For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who by their unrighteousness suppress the truth. 19 For what can be known about God is plain to them, because God has shown it to them.
God is an awesome God, and nothing will stop him from getting the gospel, the good news, to even the most remote parts of the world.
Acts 13:47 states:
For so the Lord has commanded us, saying, "'I have made you a light for the Gentiles, that you may bring salvation to the ends of the earth.’"