It is self-evident why we need God. But it is not so evident as to why God would need human beings.
We need God because Divine Love and Wisdom are the only self-existent substance and form in the universe from which all other spiritual and natural substances and forms were derived by correspondence and influx. Thus, all existential creatures including humans are sustained, governed and maintained by the Divine Love and Wisdom of God.
And, in the Bible, we are told that God consists of Father, Son and Holy Spirit. Swedenborg calls the Holy Spirit “the Divine Proceeding.” It is easy to understand that the Father is Divine Love and the Son is Divine Truth but what is the Holy Spirit or “Divine Proceeding?” We are even told that the Holy Spirit was only fully realized after Jesus (the Son or Divine Truth) was crucified, glorified and resurrected.
God is Infinite or Divine Love. But this Love is only God’s will or desire to give. If this Love or will is to be fully realized or put into effect, it must be useful in some way. This is why God needs to create the universe and human beings. He creates the universe through His form or Divine Truth. Divine Truth consists of all righteous possibilities or true ideas. But these ideas are only ideal. If Love is to become real, these ideas must be actualized. This is where the fourth dimension of time comes in. It is in this fourth dimension where the Divine Proceeding or the Holy Spirit resides. This is also where all the uses of Love proceed. It is here that Love becomes useful to all existential beings. Thus God is able to heal, maintain and sustain through the Holy Spirit.
Now, it was only when God manifested as Jesus the Messiah on earth that the Holy Spirit of Love could become real or concrete because it then could flow into the lower dimensions of matter. After Jesus resisted the temptations of hell, was crucified, glorified and resurrected, the Divine Love was fused with His human flesh and God (or Love) became Celestial-Spiritual-Natural-Material. Thus, God made His Love fully real. He proved that He loves us by coming down in the flesh, embodying our past hereditary sins, experiencing and enduring the temptations of hell and restoring equilibrium. Now, the Holy Spirit of God can completely flow into the material world through the body of Jesus. This is why in the Bible Jesus urges us to eat his flesh (Love) and drink his blood (Truth).
Therefore, God needs us because this is how He realizes His own substance (unselfish Love) by loving, healing, saving and sustaining us through His Holy Spirit. And the more human beings reciprocate this Love by entering the Kingdom of Heaven, the more this Love becomes real because Heaven is the Divine-Human body of God.
The Holy Spirit is the Divine Truth and also the Divine Energy and Operation proceeding from the one God in whom is the Divine Trinity, that is, from the Lord God the Savior. The Holy Spirit signifies strictly the Divine truth, thus also the Word; and in this sense the Lord Himself is the Holy Spirit. But since in the church at this day the Divine operation, which is actually justification, is what is meant by the Holy Spirit, this is here taken to be the Holy Spirit, and is what is chiefly treated of. This is done for the further reason that the Divine operation is effected by means of the Divine truth which goes forth from the Lord; and that which goes forth is of one and the same essence with Him from whom it goes forth, as the three things, soul, body, and what goes forth from them, together constitute one essence, which in man is purely human, but in the Lord is Divine and Human at the same time; and these after glorification are united as what is prior is with its posterior, or as essence is with its form. Thus the three essentials, called Father, Son, and Holy Spirit, are one in the Lord.
That the Lord is the Divine truth itself, or the Divine verity, has been shown above. That the Holy Spirit is the same is manifest from the following passages:
There shall go forth a Shoot out of the stock of Jesse; the spirit of Jehovah shall rest upon Him, the spirit of wisdom and of understanding, the spirit of counsel and might; and He shall smite the land with the rod of His mouth, and with the breath of His lips shall He slay the wicked; and righteousness shall be the girdle of His loins, and truth the girdle of His thighs (Isa. 11:1, 2, 4, 5).
He shall come like a narrow flood; the Spirit of Jehovah shall lift up a standard against him; then a Redeemer shall come to Zion (Isa. 59:19, 20).
The spirit of the Lord Jehovih is upon Me; therefore Jehovah hath anointed Me, He hath sent Me to preach good tidings unto the poor (Isa. 61:1; Luke 4:18).
This is My covenant; My spirit that is upon thee, and My words shall not depart out of thy mouth from henceforth and for ever (Isa. 59:21).
As the Lord is truth itself, all that goes forth from Him is truth, and this is what is meant by the Comforter, who is also called the Spirit of truth and the Holy Spirit. This is evident from the following passages:
I tell you the truth: It is expedient for you that I go away; for if I go not away the Comforter will not come unto you, but if I go away I will send Him unto you (John 16:7).
When He, the Spirit of truth, is come, He will guide you into all truth for He will not speak from Himself, but whatsoever things He shall hear shall He speak (John 16:13).
He shall glorify Me; for He shall take of Mine and shall declare it unto you. All things whatsoever the Father hath are Mine therefore said I that He shall take of Mine and shall declare it unto you (John 16:14, 15).
I will ask the Father to give you another Comforter, the Spirit of truth; whom the world cannot receive because it seeth Him not, neither knoweth Him; but ye know Him, for He abideth with you and shall be in you. I will not leave you orphans; I come to you: and ye shall see Me (John 14:16-19).
When the Comforter is come whom I will send unto you from the Father, the Spirit of truth, He shall bear witness of Me (John 15:26).
He is called the Holy Spirit (John 14:26).
That by “the Comforter” or “the Holy Spirit” the Lord meant Himself, is evident from His words, that the world had not yet known Him:
But ye know Him; I will not leave you orphans; I come to you; ye shall see Me (John 14:17-19);
and in another passage:
Lo I am with you always, even unto the consummation of the age (Matthew 28:20);
also from these words, “He shall not speak from Himself,” but “He shall take of Mine.”
Since, then, by the Holy Spirit the Divine truth is meant, and the Divine truth was in the Lord and was the Lord Himself (John 14:6), and since the Holy Spirit could therefore proceed from no other source, it is said:
The Holy Spirit was not yet, because Jesus was not yet glorified (John 7:39),
and after the glorification:
He breathed upon His disciples and said, Receive ye the Holy Spirit (John 20:22).
The Lord breathed upon His disciples and said this because “breathing upon, (aspiratio)” was an outward symbol representative of the Divine breathing-into (inspiratio). Breathing-into effects insertion into angelic societies. From all this the understanding can comprehend what was said by the angel Gabriel respecting the conception of the Lord:
The Holy Spirit shall come upon thee, and the power of the Most High shall overshadow thee therefore that holy thing which shall be born of thee shall be called the Son of God (Luke 1:35).
The angel of the Lord said to Joseph, in a dream, Fear not to take unto thee Mary thy bride; for that which is conceived in her is of the Holy Spirit. And Joseph touched her not until she had brought forth her firstborn Son (Matt. 1:20, 25).
Here the “Holy Spirit” means the Divine truth going forth from Jehovah the Father; and this going forth is the power of the Most High which then overshadowed the mother. This, therefore, agrees with what is said in John:
The Word was with God, and God was the Word. And the Word became flesh (1:1, 14).
That by “the Word” here the Divine truth is meant may be seen above (n. 3) on The Faith of the New Church. Emanuel Swedenborg [TCR 139-140]