Jesus Christ is the Son of God. He is part of the trinity that existed before the foundation of the world. He is the Word that was there from beginning and all things were created through Him. In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. All things were made through Him, and without Him nothing was made that was made. In Him was life, and the life was the light of men. (John 1:1-4).
All the fullness of God dwells in Jesus Christ. For it pleased the Father that in Him all the fullness should dwell, (Colossians 1:19). For in Him dwells all the fullness of the Godhead bodily; (Colossians 2:9).
Jesus Christ is the head of the Church. And He put all things under His feet, and gave Him to be head over all things to the church, (Ephesians 1:22). For the husband is head of the wife, as also Christ is head of the church; and He is the Savior of the body. (Ephesians 5:23) And He is the head of the body, the church, who is the beginning, the firstborn from the dead, that in all things He may have the preeminence.( Colossians 1:18)