How old is God?  No one really knows because Gos is timeless; always was, always will be.   Even those Christian groups that insist the Earth is only 6,000 years old believe God created it so God has to be at least 6000 years old.  And if Christ is a part of God, than Christ must be at least 6,000 years old.     So how do we explain the Christian ministers teaching that anyone who  hasn't read the gospel cannot go to heaven.  What about Moses and the many other Old Testament prophets?  Are they banned from heaven because the gospels hadn't been written yet?  I don't think so.
    God has been around since long before the material universe was created some 15 billion years ago.  And the ancient people in many parts of the world worshiped God much more fervently than people do today.  So to believe that these ancients can never go to heaven because they never read the Gospels is the hight of egotism on the part of some modern Christian churches and preachers.  Egotism, because what they are saying is they are better than the ancients because they have the gospels, often memorized but with little understanding of the true spiritual meaning.
    Even the ancient Egyptians, Greeks and Romans believed in and worshiped God.  They may have had a pantheon of gods like the Olympians of Greece, but they almost always recognized that there was only one true God who was greater than the gods.   Some recognized that the gods were really the fallen angels,some didn't, but they all worshiped God.