“We all know that like begets like and that for the offspring to grow to the stature of his parent is a process infinitely repeated in nature. We can therefore understand that for a son of God to grow to the likeness of his Father in heaven is in harmony with natural law. We see this law demonstrated every few years in our own experience. Sons born to mortal fathers grow up to be like their fathers in the flesh. This is the way it will be with spirit sons of God. They will grow up to be like their Father in heaven. Joseph taught this obvious truth. As a matter of fact, he taught that through this process God himself attained perfection. From President Snow’s understanding of the teachings of the Prophet on this doctrinal point, he coined the familiar couplet: ‘As man is, God once was; as God is, man may become.’ This teaching is peculiar to the restored gospel of Jesus Christ.”
Marion G. Romney, General Conference Report (Salt Lake City, UT: The Church of Jesus Christ of Latter-day Saints, 3 October 1964), 50.