But when the fulness of the time was come, God sent forth his Son, made of a woman, made under the law, To redeem them that were under the law, that we might receive the adoption of sons. And because ye are sons, God hath sent forth the Spirit of his Son into your hearts, crying, Abba, Father.  (Galatians 4:4-6)

The Incarnation was the Father’s plan. There is one eternal God, eternally manifest in three persons; Father,Son and Holy Ghost. God has always been the Father, and by him Fatherhood derives its essence. Forever there has been in the Godhead, the eternal Son. The Son honors the Father, and the Father loves the Son.

Eternally proceeding from the Father and the Son, is the Paraclete, the Holy Spirit who comes from the Father and the Son. There is one God, in an eternal communion of love;Father, Son, and Holy Spirit.

The Father knew before we were created that He would give us free will, and that consequently we would all sin. He also knew that  sin would estrange us from the Father and the Son, necessitating eternal judgment for the transgressors.

Therefore God determined to send His Son into the world to die for sinners, as a sacrifice of substitution.

There is an amazing record in the Psalms,  of conversation between the Father and the Son in eternity, concerning our salvation;

Sacrifice and offering thou didst not desire; mine ears hast thou opened: burnt offering and sin offering hast thou not required. Then said I, Lo, I come: in the volume of the book it is written of me, I delight to do thy will, O my God: yea, thy law is within my heart.(Psalm 40:6-8)

The Son is speaking to the Father, about what He truly requires and about what He doesn’t really want. It is not the sacrifices and gifts of animal blood and fat as later required by the law ordained of God. What does the Father truly require?

The Father requires a life, a truly human life of loving obedience, fellowship, and of worship. When the Son says “My ears thou hast opened…”, he is literally saying, my ears you have pierced, in reference to the ritual of the bond-slave in Exodus.

And if the servant shall plainly say, I love my master, my wife, and my children; I will not go out free: Then his master shall bring him unto the judges; he shall also bring him to the door, or unto the door post; and his master shall bore his ear through with an aul; and he shall serve him for ever.(Exodus 21:5-6)

The Son of God came into the world as the bond-slave of God, sold out to do the will of the Father as a human being, even unto death.

The entire “Volume of the Book” of scripture is all centered around the revelation of the Son of God, the one who came to joyfully do the Will of the Father. In another pre-incarnate conversation between the Father and the Son, the Father calls the Son God, and promises him the “oil of Joy”;

Thy throne, O God, is for ever and ever: the sceptre of thy kingdom is a right sceptre. Thou lovest righteousness, and hatest wickedness: therefore God, thy God, hath anointed thee with the oil of gladness above thy fellows.(Psalm 45:6-7)

Perhaps the most quoted of these amazing conversations within the Godhead, is Psalm 110, in which the Father decrees that the Son would be both a ruling King and a “Priest forever”.

The Lord said unto my Lord, Sit thou at my right hand, until I make thine enemies thy footstool. The Lord shall send the rod of thy strength out of Zion: rule thou in the midst of thine enemies. Thy people shall be willing in the day of thy power, in the beauties of holiness from the womb of the morning: thou hast the dew of thy youth. The Lord hath sworn, and will not repent, Thou art a priest for ever after the order of Melchizedek…(Psalm 110:1-4)

What is a priest? A Mediator, someone whose life is consecrated to bring men to God, and God to men. The Father swore to the Son in eternity past, that He(Jesus) would be a “Priest forever” for us. He would be able to bring God and man together, for He alone is both God and Man.

Isaiah prophesied, “For unto us a child is born…(Man)… and unto us a Son is given…(God)…”. Men in their weakness would need a priest who understands our infirmities, weakness and sorrows. But God requires a human being who is absolutely faithful and completely Holy. Jesus is the only person who completely satisfies each requirement.

When the fulness of time came, the Father in heaven ‘sent the Son’ into the world to save the world. When the letter to the Hebrews quotes Psalm 40 it read thus;

Wherefore when he cometh into the world, he saith, Sacrifice and offering thou wouldest not, but a body hast thou prepared me: In burnt offerings and sacrifices for sin thou hast had no pleasure. Then said I, Lo, I come (in the volume of the book it is written of me,) to do thy will, O God.(Hebrews 10:5-7)

The Son would need a body. In Mary’s womb, God had prepared one for the Savior to come into the world through.The time had come for salvation to arrive.