What a beautiful question.
It is because He replaces us. As we are becoming children of light, He replaces us, cause He is that light. That light is love.God is Love.
(I wrote now from the perspective of the time dimension on earth, when I wrote becoming children of light, in heaven all is forever, and I have been instructed by God to tell those who wants to know, that the ones who choose the light, is the light) Getting baptized is choosing the light, killing the old man, choosing to be replaced by God when done right.
When we are totally replaced by His light we are in heaven, Heaven is where God is, and God is light, God is Love.
Thus the son of man comes with the lightning.
It is so beautiful to be replaced by God, to be replaced by He who is good, to get away from all dirt, to see and feel pure ecstasy and Love. Humans are not capable of Love. When we truly Love, we are replaced by God who is Love.
7Beloved, let us love one another, because love comes from God. Everyone who loves has been born of God and knows God. 8
Whoever does not love does not know God, because God is love
5
And this is the message we have heard from Him and announce to you: God is light, and in Him there is no darkness at all.