God has already revealed Himself in His word, the Bible. The question may be revised to say, “why has not God revealed Himself to me the way I want Him to reveal himself?” God’s methods and plans are far beyond our human capabilities. He says, “For as the heavens are higher than the earth, so are my ways higher than your ways, and my thoughts than your thoughts.” (Isaiah 55:9) If we want to know God, we must study the Bible.
God purposed to have human beings “fill” the earth, Genesis 1:28. He also desired all mankind to have the knowledge of good and evil, but that knowledge is only obtained by the experience of both good and evil. So, God in his wisdom has permitted mankind to choose their own ways thereby reaping the consequences of their mistakes. At the same time, man is populating the earth. When the earth has been sufficiently filled and the lessons of evil learned, then God will show all men the proper way to live. He will reveal Himself in a way that all will understand as promised in 1 Timothy 2:4, “Who will have all men to be saved, and to come unto the knowledge of the truth.”
As a drunken man finally comes to the realization that if he continues in his drunkenness it will result in death, so when mankind has had their fill of evil, they will turn to the Lord. Then shall come to pass: Hosea 2:23. “I will have mercy upon them that had not obtained mercy; and I will say to them which were not my people, Thou art my people; and they shall say, Thou art my God.”
This is also foretold in Revelation 21:2-5, “And I John saw the holy city, new Jerusalem, coming down from God out of heaven…And I heard a great voice out of heaven saying, Behold, the tabernacle of God is with men, and he will dwell with them, and they shall be his people, and God himself shall be with them, and be their God. And God shall wipe away all tears from their eyes; and there shall be no more death, neither sorrow, nor crying, neither shall there be any more pain: for the former things are passed away. And he that sat upon the throne said, Behold, I make all things new. And he said unto me, Write: for these words are true and faithful.”