At the beginning of his gospel (Jn. 1:10), John wrote of the Son of God, “He was in the world, and the world was created through him, but the world did not know him.” It was revealed to Paul that from the beginning of creation, the Son of God had also been unknown in heaven. Paul spoke of “the mystery of the Father and the Son” (Col. 2:2), “the mystery that was hidden from the Aeons (heavenly beings) and from generations of man, but now is revealed to His saints” (Col. 1:26). This mystery, hidden from the beginning of time, was that there had been a Son somewhere in heaven with God, through whom God had created everything. Nobody in heaven or earth knew that the Son existed until the Son was revealed in the man, Jesus Christ.
This means that at the beginning of his gospel, John could also have written this about the Son: “He was in heaven, and heaven was created through him, but heaven did not know him” (Jn. 1:10).