As we read in the bible we only read about the presence of God in the area of the Old and New Testaments (Middle East, Greece, Rome, etc). Where was God for the rest of the world (China, North America, Island Nations, etc.)? Why didn’t he appear to them?
Just because we do not have a record of God’s appearing in other areas of the world doesn’t mean that He didn�t do that.
In the times of the Old Testament, God made a special covenant with the people of Israel that He didn’t make with the other nations (Exodus 19:5, 6, Deuteronomy 7:6, 14:2). So God dealt specially with the children of Israel in ways that He didn’t deal with the rest of the nations. God did send prophets to some Gentile nations as illustrated in the book of Jonah.
In the New Testament, Jesus told the apostles in Matthew 28:18-20 and Mark 16:15, 16 to preach the gospel to all the world. This was about 30 A.D. Paul says in Colossians 1:23 that the gospel was preached to every creature under heaven. This was around 60 A.D. So every person who lived on the world in that day heard God’s message at that time. I have no doubt that the Lord aided them in their efforts to accomplish this task. Sometimes he even transported them miraculously to new places (Acts 8:39).
The bottom line is that the Bible teaches that God is present everywhere (Psalm 24:1) and that He doesn’t necessarily tell everything that He does to all men (Psalm 50:12). There are some things that are hidden from man’s knowledge (Deuteronomy 29:29, Romans 11:33). We must be concerned with the things that God reveals to us today in His word.
We can be assured that God is a just, holy, and merciful God and that His judgment will be fair and reasonable in that regard (Psalm 89:14).