God has revealed Himself to us through the Scriptures and through His creation.
God reveals Himself through the gospel penned by John.
16For God so loved the world, that He gave His only begotten Son, that whoever believes in Him shall not perish, but have eternal life.
17For God did not send the Son into the world to judge the world, but that the world might be saved through Him.
18He who believes in Him is not judged; he who does not believe has been judged already, because he has not believed in the name of the only begotten Son of God.
19This is the judgment, that the Light has come into the world, and men loved the darkness rather than the Light, for their deeds were evil.
20For everyone who does evil hates the Light, and does not come to the Light for fear that his deeds will be exposed.
John 3:16-20 NASB
Penned by a common man.....Why didn't God reveal Himself to the other nations of the world in order to eliminate any future confusion such as this?
Or maybe He did as evidenced in the other religions who worship their own form of God...........