D&C 34

The Savior addressed Orson Pratt with -

"My son Orson..."  (Doctrine and Covenants 34:1)

...declaring

"...hearken and hear and behold what I, the Lord God, shall say unto you, even Jesus Christ your Redeemer;

2 The light and the life of the world, a light which shineth in darkness and the darkness comprehendeth it not..."  (Doctrine and Covenants 34:1–2)

And then explaining His reference to "my son" - 

"Who so loved the world that he gave his own life, that as many as would believe might become the sons of God. Wherefore you are my son;

4 And blessed are you because you have believed..."  (Doctrine and Covenants 34:3–4)

Obviously, if we truly believe (obedience) then we become His son or daughter.