“For although they knew God, they never glorified him as God nor gave thanks to him but their thinking became futile and their foolish hearts were darkened. Although they claimed to be wise, they became fools and exchanged the glory of the immortal God for images made to look like mortal man and birds and animals and reptiles.” Romans 1:22
So you see, people have had ample opportunity to follow God and He could very well have said—that’s it, it’s over. But God who is love gave even more opportunities for people to know Him.
In his book, “Eternity in Their Hearts”, Don Richardson reports that God gave visions to many ancient peoples which prepared them for the day when a man would bring them The Book of Truth which they once had and lost.
The Karen people of Burma had expected from “time immemorial” a white brother who would bring them a book of Y’wa (amazingly close the Hebrew “YHWH” or “Yahweh”), The Supreme God. They waited but while they waited, the Bukhos whom the Karen accepted as prophets of Y’wa , reminded them that the ways of Y’wa were different from the ways of demons and that Buddhism was not Y’wa’s way. They taught them hymns, which had been passed down for generations. One hymn described Y’wa as forming the world, giving “two persons detailed instructions” to avoid the “fruit of trial” but they didn’t obey nor believe. “Mu-kaw-lee deceived two persons. He caused them to eat the fruit of the tree of trial” From then on they had sickness, aging and death. Their story sounds very much like the account in Genesis 2 (the first book in the Old Testament of the Bible) of Adam and Eve in the Garden of Eden eating from The Tree of the Knowledge of Good and Evil. God specifically told them not to eat that one fruit but the serpent enticed Eve. The result was sin, sickness, and death (and any other bad thing you can name).