Relevant Words of God:
God’s saving of man is not done directly using the method of the Spirit and the identity of the Spirit, for His Spirit can neither be touched nor seen by man, neither can man draw near. If He tried to save man directly using the perspective of the Spirit, man would be unable to receive His salvation. If God did not put on the outward form of a created man, there would be no way for man to receive this salvation. For man has no way of approaching Him, much as no one was able to go near the cloud of Jehovah. Only by becoming a created human being, that is, only by putting His word into the body of flesh that He is about to become, can He personally work the word into all who follow Him. Only then can man personally see and hear His word, and moreover enter into possession of His word, and by this means come to be fully saved. If God did not become flesh, no man of flesh and blood would be able to receive such great salvation, nor would a single man be saved. If the Spirit of God worked directly in the midst of mankind, all humanity would be struck down, or else, with no way of coming into touch with God, they would be completely carried away captive by Satan. The first incarnation was to redeem man from sin, to redeem him by means of the fleshly body of Jesus, that is, He saved man from the cross, but the corrupt satanic disposition still remained within man. The second incarnation is no longer to serve as a sin offering but rather to save fully those who were redeemed from sin. This is done so that those who have been forgiven may be delivered from their sins and made fully clean, and by attaining a changed disposition, break free of Satan’s influence of darkness and return before the throne of God. Only in this way can man be fully sanctified.
from “The Mystery of the Incarnation (4)” in The Word Appears in the Flesh