THE TRINITY; THE FULNESS OF HIS BEING
THEY who are truly men of the Church, that is, who are in love to the Lord and in charity toward the neighbor, know and acknowledge a Trine. Still, they humble themselves before the Lord, and adore Him alone, inasmuch as they know that there is no approach to the Divine Itself, called the Father, but by the Son; and that all that is holy, and of the Holy Spirit, proceeds from Him. When they are in this idea, they adore no other than Him, by Whom and from Whom are all things; consequently they adore One.
—Arcana Coelestia, n. 2329
God is one in essence and in person. This God is the Lord. The Divinity itself, which is called Jehovah "the Father," is the Lord from eternity. The Divine Humanity is "the Son" begotten from His Divine from eternity, and born in the world. The proceeding Divinity is "the Holy Spirit."
—Divine Providence, n. 157