Christadelphians believe that Jesus of Nazareth, born of the Virgin Mary, is the Son of God. His miraculous birth, which came apart from the intervention of man, was by the Holy Spirit. The spirit of God is the power by which God sustains the universe. The Holy Spirit is that same power, when used by God for a specific purpose. God used that power to specially prepare Jesus to exhibit His character to the world.
II.--That Jesus of Nazareth was the Son of God, begotten of the Virgin Mary by the Holy Spirit, without the intervention of man, and afterwards, anointed with the same spirit, without measure, at his baptism.
The Greek word translated "Word" in the above verse is "logos" and it means "the plan." But more than just the plan, it is all the detail that goes into creating, forming, and carrying out the plan. It means the full embodiment of the plan. The plan was God, in that the purpose of God from the beginning was fully encompassed and accomplished in this plan.
This was Jesus' relation to the plan. He was determined by God from the very beginning to be the fulfillment of the plan, and to be the complete exhibition of God's character in flesh. He was God manifested (exhibited) in flesh. (1TI. 3:16)
Jesus was necessitated in the plan of God, because of the disobedience that man would fall into as a result of events in the Garden of Eden. A way had to be found which would condemn sin as the wickedness it truly is, while at the same time providing a door to life for repentant sinners. Hence Christadelphians believe:
III.--That the appearance of Jesus of Nazareth on the earth was necessitated by the position and state into which the human race had been brought by the circumstances connected with the first man.