I have been asked, "Why hasn't God left a witness of Himself so that people around the world will know of Him and will be drawn to Him for salvation? What about those who have never heard of Him? Is it fair that they go to Hell?"
The Bible tells us that all those who die without knowing Jesus Christ as their Saviour will be lost for ever in Hell. Sadly many will go that way that leadeth to destruction (Matthew 7:13). Some ask if that is fair. God is completely just. I would not call Him "fair." I do not want Him to be fair. If He was fair, He would give everyone what they deserve, and we all deserve eternity in HELL! Let me reiterate--I don't want Him to be fair, and neither should anyone one else who understands their sinful condition. "There is NONE that doeth good, no not one" (Romans 3:10-20,23). But God has made a way so that anyone who believes on Him can be saved (John 3:16), for He is not a respecter of persons (Acts 10:34).
"The Lord is not slack in His promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance" (II Peter 3:9). He desires for all people to come to salvation through faith in Jesus. Jesus told his disciples to "Go ye therefore, and teach ALL NATIONS..." (Matthew 28:19), "Go ye into all the world and preach the Gospel to EVERY CREATURE" (Mark 15:16), "...Ye shall be witnesses unto me both in Jerusalem, and in all Judaea, and in Samaria, and unto the UTTERMOST PART OF THE EARTH" (Acts 1:8). They were to preach the gospel to every nation, every tribe, every person. In Heaven, there will be people from every people group, every tribe, every language. This is a part of the song of praise those people will sing to the Lord Jesus Christ, God the Son: "...for thou wast slain, and hast redeemed us to God by thy blood out of every kindred, and tongue, and people, and nation" (Revelation 5:9).
God has made Himself known in many ways "God, who at sundry times and in divers manners spake in time past unto the fathers by the prophets..." (Hebrews 1:1). So each generation has had a testimony from the Lord.
Did you know that God has NOT left Himself without witness? He has given a fourfold testimony to people.
The Creation: "The heavens declare the glory of God; and the firmament sheweth his handywork. Day unto day uttereth speech, and night unto night sheweth knowledge. There is no speech nor language, where their voice is not heard. Their line is gone out through all the earth, and their words to the end of the world..." (Psalm 19:1-4). The creation, the heaven and the earth, declare God's existence and character, so that all are without excuse (Romans 1:20).
The Care: "...Nevertheless he left not himself without witness, in that he did good, and gave us rain from heaven, and fruitful seasons, filling our hearts with food and gladness" (Acts 14:15-17). He gives rains and sunshine to the just and the unjust (Matthew 5:45). God has provided so much for our care, things that we need. He did this that we might seek him, as Paul preached on Mars Hill (Acts 17:27).
The Conscience: "For when the Gentiles, which have not the law, do by nature the things contained in the law, these, having not the law, are a law unto themselves: Which shew the work of the law written in their hearts, their conscience also bearing witness, and their thoughts the mean while accusing or else excusing one another;) In the day when God shall judge the secrets of men by Jesus Christ according to my gospel" (Romans 2:14-16). The conscience bears witness of right and wrong.
The Canon: "So then faith cometh by hearing, and hearing by the word of God" (Romans 10:17) This is most very evident (Psalm 19:7-11), (II Timothy 3:14-17). He has given unto us the holy, infallible, perfect word of the living God, the canon of Scripture, the Bible. From creation to Christ, from beginning to end, it is the greatest testimony and and specific witness of the Lord, and we are to go and use it to "preach the gospel to every creature" (Mark 16:15, II Peter 1:19-21).
There are some books that tell of some of the redemptive analogies that God has put in cultures to give them opening to the Gospel. A couple of them are Eternity in Their Hearts and Peace Child by missionary Don Richardson.
I hope this is helpful in sharing how God has extended love and longsuffering (similar to patience) to all humanity, and has provided the "...Saviour, which is Christ the Lord" (Luke 2:11) to save us from all our sins. If we reject the witnesses He has given, and the way of salvation He has provided, then it is OUR fault, not God's.