God the Father is the only source of divinity, which can not be duplicated. He is the principle and owner of unity among the three hypostases. He was not born and did not proceed from anything. The remaining two hypostases (the Son and Holy Spirit), which are of one essence with the Father but not in principality or ownership, were originated from God the Father and are determined by their relationships with him.
God the Son, Jesus Christ, had two births: eternal from the Father, and in the time of Pontius Pilate, from Virgin Mary. The Holy Spirit, in turn, proceeded eternally from the Father, and sent to the world in time through Christ the Son. Christ said: " But when the Comforter is come, whom I will send unto you from the Father, even the Spirit of truth, which proceedeth from the Father, he shall testify of me" (John 15: 26).
Nature of Christ:
Jesus Christ is the incarnated God the Word. Has a full divinity and full humanity. His human nature is united with his divine nature (present since eternity), which took place from the first moment of the Holy Pregnancy in the Virgin's womb, where a hypostasis with two natures, divine and human, was formed. His two natures remain distinct, without mixture or change; one does not absorb the other, united permanently in the same person.
There was no separation between Christ’ divinity and humanity when he died on the cross, but his soul was separated from his body, while his divinity was never separated from neither his soul nor his body. Thus, his soul, united with his divinity, went to Abaddon to preach the deceased with hope, open the doors of heaven for them, and bring them in. His body remained in the grave united with his divinity, until the third day when his soul, united with his divinity, came to re-unite with his body, united with his divinity, and so was the resurrection.