IN INCARNATION
The creation by God was for the old creation, but the incarnation is for the new creation. John 1:14 reveals that [the Triune] God became incarnated. The entire God—the Father, the Son, and the Spirit—was involved in the incarnation. This is also proved by other verses in the New Testament. Galatians 4:4 says, "God [the Father] sent forth His Son, come of a woman." God the Father took part in the incarnation. It was the Son’s incarnation, but the Father sent the Son. In John 8:29 the Lord Jesus said, "He who sent Me is with Me." The Father sent the Son, and the Son said that the One who sent Him was with Him. Thus, the Son’s incarnation is also the Father’s incarnation. After sending the Son, the Father did not remain in the heavens. When the Son came in the womb of Mary, the Father was with the Son.
Matthew 1:20 says, "That which is begotten in her is of the Holy Spirit." Jesus was begotten in Mary, and Jesus was of the Holy Spirit. These main verses show that the incarnation was not only of the Son but also of the Father and of the Spirit. All Three of the Divine Trinity were incarnated. The birth of Jesus was with the Triune God. He was the complete God and the perfect Man, the Triune God-man. He was the Triune God incarnated, the God who is the Father, the Son, and the Spirit. The incarnation was the incarnation of the Father, the Son, and the Spirit. The very Savior in whom we believe and whom we have received is the wonderful Triune God-man.
IN THE LIVING AND WORK IN JESUS’ HUMANITY
The Triune God was in Jesus’ living and work while He was on the earth. In John 8:29 the Lord Jesus said, "He [the Father] who sent Me [the Son] is with Me [the Son]." In the Son’s living and work, the Father was with Him (John 16:32b). When the Son spoke, the Father did His works in the Son (John 14:10). Luke 4:1 tells us that Jesus [the Son], full of the Holy Spirit, was led by the Spirit. He was with the Father and full of the Spirit. In His living and in His work, the Spirit was with Him as well as the Father. Matthew 12:28 says that the Son cast out demons by the Spirit. The Son did not cast out demons without the Spirit, and He did not speak without the Father. When He spoke, the Father did His works. When He cast out demons, He did it by the Holy Spirit. The Divine Trinity was wrapped up with the living and work of Jesus while He was on this earth.
IN HIS CRUCIFIXION
The Divine Trinity can also be seen in the crucifixion of Jesus. First John 1:7 and Acts 20:28 show that the blood of Jesus [the Son] was considered as the blood of God [including the Father and the Son]. How could the very God have had blood? He had blood because He was mingled with a man. In God as the divine One alone, there is no blood. But in the man with whom He mingled Himself there is blood. This God-man is one entity with two natures. In the divine nature there is no blood, but in the human nature there is blood; so the blood of Jesus is considered as the blood of God. Acts 20:28 says that God obtained the church "through His own blood," and 1 John 1:7 refers to the blood of Jesus, the Son of God. When Jesus died on the cross, God died there. One line from a famous hymn by Charles Wesley says, "Amazing love! How can it be that Thou, my God, shouldst die for me?" (see Hymns, #296). Charles Wesley was strong to point out that his God died for him. Jesus, the God-man, died on the cross for all of us.
Hebrews 9:14 says that Christ offered Himself through the eternal Spirit. Jesus, in Himself alone, could not accomplish His crucifixion. To die on the cross as an offering to God, the Son needed the Spirit. Jesus did not die on the cross alone and separate from the Spirit. The Spirit was one with the Son. The Son died on the cross with the Father and by the Spirit. The Father, the Son, and the Spirit were all involved in the Son’s crucifixion. The death of Christ was not only the death of the man Jesus but also the death of the Son with the Father and by the Spirit. Because Christ offered Himself through the eternal Spirit, His death is eternally effective. Our co-crucifixion with Christ on the cross (Gal. 2:20) is realized in the eternal Spirit who indwells us.
(Living In and With the Divine Trinity, Chapter 1, by Witness Lee)