I look at it this way: when we talk about being saved through Jesus' blood we must remember how this came about...JESUS VOLUNTARILY SHED HIS BLOOD! Jesus, who is God, voluntarily became a man for awhile so He could live a sinless life as a man, thus providing us with His perfect example, became a man so he fould suffer and feel pain as we do, became a man so He could have blood to be shed through His suffering, became a man so He, after living a sinless life and introducing the New Covenant, could die and pay the penalty for OUR sins.
We should be thankful as our human nature can allow us when we realize HE, the REAL GOD, did something no fictional god has ever been credited with doing...DYING FOR HIS OWN CREATIONS, and dying a most shameful and painful death...so He could be raised from the dead, overcoming the works of the devil, then assuming His rightful place at His Father's right hand.
He was in a human body, and Mary is always called His mother. I have no idea what physical process God used to convert Him into a man, but I know He did it and that some day He Himself will tell us how. Who's to say right now what the makeup of His Deoplasm was at His incarnational conception?