“Behold, I Am the Light and the Life of the World”
Doctrine and Covenants 12:9
9 Behold, I am the light and the life of the world, that speak these words, therefore give heed with your might, and then you are called. Amen.
Elder Hyrum M. Smith and Janne M. Sjödahl wrote:
“It is our Lord who is speaking [here]. He calls Himself the Light and the Life of the World, adopting the terms which the Apostle John loved so well [see John 1:4, 9; 3:19, 6:35; 12:35; 14:6]. The Savior frequently quotes in these Revelations; or rather, expressions familiar to the readers of John’s writing meet us here again and again. John had a prominent part in the ushering in of this dispensation. On the Isle of Patmos he saw the coming, in our day, of the ‘mighty angel’ with the ‘little book open,’ and it was said to him, ‘Thou must prophesy again before many peoples, and nations, and tongues, and kings’ (Rev. 10:11). In fulfilment of this prediction, he and two fellow Apostles conferred the Melchizedek Priesthood upon Joseph Smith and Oliver Cowdery. No wonder if the spirit of the teachings of these Apostles, and especially that of John, the last of the first Twelve, should be discernible in these Revelations.”
(The Doctrine and Covenants Commentary, rev. ed. [1951], 67.)