It is explained at some length in Heaven and Hell [Sections 78–86] that God is human and that because of God all angels and spirits are human, and there will be more on this topic in the books about angelic wisdom.
While from the beginning God was human on the first [or innermost] level, he was not yet human on the last [or outermost] level. After he took on a human nature in the world, though, he also became human on the last [or outermost] level. This follows from what has been shown above [Sections 29–35], namely, that the Lord united his human nature with his divine nature and in this way made his human nature divine as well.
That is why the Lord is called the Beginning and the End, the First and the Last, and the Alpha and the Omega. This is in the Book of Revelation:
“I am the Alpha and the Omega, the Beginning and the End,” says the Lord, “who is and who was and who is to come, the Almighty.” (Revelation 1:8, 11)
When John saw the Son of Humanity in the midst of the seven lampstands,
[John] fell at his feet as dead, but [the Son of Humanity] laid his right hand on him, saying, “I am the First and the Last.” (Revelation 1:13, 17; 2:8; 21:6)
Behold, I am coming quickly, to give to all according to what they have done. I am the Alpha and the Omega, the Beginning and the End, the First and the Last. (Revelation 22:12, 13)
And in Isaiah,
Thus says Jehovah the King of Israel, and Israel’s Redeemer, Jehovah Sabaoth: “I am the First and the Last.” (Isaiah 44:6; 48:12)
from The Lord, Section 36
Sections 78-86 from Heaven and Hell: Published 3/28/2018-3/30/2018
Sections 29-35 from The Lord: Published 3/31/2018-4/7/2018