"God, after He spoke long ago to the fathers in the prophets in many portions and in many ways, in these last days has spoken to us in His Son..."
Hebrews 1:1, 2
Jesus, the Author of the Faith:
"And He is the image of the invisible God, the firstborn of all creation. For in Him all things were created, both in heaven and on earth, visible and invisible, whether thrones or dominions or rulers or authorities -- all things have been created through Him and for Him. And He has existed prior to all things, and in Him all things endure."
"Therefore, when He comes into the world, He says,
'Sacrifice and offering Thou hast not desired,
But a body Thou hast prepared for Me...'
Then I said, 'Behold I have come (In the roll of the book it is written of Me)
To do Thy will, O God.'
By this will we have been sanctified through the offering of the body once and for all."
Hebrews 10:5-7, 10
Jesus, the Perfecter of the Faith:
"In the days of His flesh, when He offered up both prayers and supplications with loud crying and tears to Him who was able to save Him out of death, and who was heard because of His piety, although He was a Son, He learned obedience from the things that He suffered; and having been made perfect, He became to all those who obey Him the source of eternal salvation..."
"The second person in God, the Son, became a human Himself, was born into the world as an actual man -- a real man of a particular height, with hair of a particular color, speaking a particular language, weighing so many stone. The eternal being, who knows everything and created the whole universe, became not only a man but (before that) a baby, and before that a fetus inside a woman's body.
The result of this was that you now had one man who really was what all men were intended to be: one man in whom created life, derived from His mother, allowed itself to be completely and perfectly turned into the begotten life. The natural human creature in Him was taken up fully into the divine Son. Thus in one instance humanity had, so to speak, arrived; had passed into the life of Christ. And because the whole difficulty for us is that the natural life has to be in a sense, 'killed,' He chose an earthly career that involved the killing of His human desires at every turn -- poverty, misunderstanding from His own family, betrayal by one of His intimate friends, being jeered at and manhandled by the police, and execution by torture. And then, after thus killed -- killed every day in a sense -- the human creature in Him, because it was united to the divine Son, came to life again. The Man in Christ rose again; not only the God. That is the whole point. For the first time we saw a real man."
Jesus did not masquerade as a man. He was a man.
"For it was fitting for Him, for whom are all things, and through whom are all things, in bringing many sons to glory, to perfect the author of their salvation through suffering."
"...and having been made perfect, He became to all those who obey Him the source of eternal salvation..."
"...let us also lay aside every encumbrance, and the sin which so easily entangle us, and run the race that is set before us, fixing our eyes on Jesus, the author and perfecter of the faith."
Hebrews 12: 1, 2