See 3 Nephi 1:27, 36. “Without question Elohim and Jehovah—though separate as personages—are one: one in mind, one in purpose, one in glory. Indeed, they are infinitely inure one than they are separate.
This has properly been referred to as the greatest teaching device ever devised in all eternity (see Promised Messiah, p. 131). The whole plan of salvation centers in our learning to be one with Christ as he is one with the Father. The doctrine of oneness is the doctrine of salvation.” (Commentary 2:230.)