Excerpt from Arcana Cœlestia ~ Emanuel Swedenborg
"the celestial of the spiritual," ... is meant the Lord; the same may also be said abstractedly of Him, because He [the Lord] is the celestial itself and the spiritual itself, that is, good itself and truth itself.As regards man, these cannot indeed be conceived of abstractedly from person, because what is natural is adjoined to everything of his thought; nevertheless, when we consider that everything in the Lord is Divine, and that the Divine is above all thought, and altogether incomprehensible even to the angels, consequently if we then abstract that which is comprehensible, there remains being and coming-forth itself, which is the celestial itself and the spiritual itself, that is, good itself and truth itself.
Nevertheless, as man is such that he can have no idea of thought whatever about abstract things unless he adjoins something natural which has entered from the world through the senses (for without some such natural thing his thought perishes as in an abyss and is dissipated), therefore lest what is Divine should perish in man when he is wholly immersed in bodily and earthly things, and with whomsoever it remained it should be defiled by an unclean idea, and together with what is Divine everything celestial and spiritual thence derived should also perish, it pleased Jehovah to present Himself such as He actually is, and such as He appears in heaven, namely, as a Divine Man. For everything of heaven conspires to the human form, as may be seen from what has been shown at the end of the chapters [in the works: Arcana Cœlestia] concerning the correspondence of all things of man with the Grand Man, which is heaven. This Divine, or this of Jehovah in heaven, is the Lord from eternity. The same the Lord took also upon Him when He glorified or made Divine the human in Himself, as is very evident from the form in which He appeared before Peter, James, and John, when He was transfigured —
And after six days Jesus taketh Peter, James, and John his brother, and bringeth them up into an high mountain apart, And was transfigured before them: and his face did shine as the sun, and his raiment was white as the light. (Matt. 17:1, 2)and also in which He at times appeared to the prophets. It is from this that everyone is able to think of the Divine Itself as of a Man, and at the same time of the Lord, in whom is all the Divine, and a perfect Trinity, for in the Lord the Divine Itself is the Father, this Divine in heaven is the Son, and the Divine thence proceeding is the Holy Spirit. That these are a one, as He Himself teaches, is hence manifest.
(from Arcana Cœlestia 5110:2,3)