Some have characterized the Biblical Unitarian view as making Christ into a "mere man." Though we do consider him a pure and genuine human being, he is not "merely" anything. Jesus is unique; he is God's supernaturally-conceived and only begotten son (John 3:16), he is the uniquely empowered agent of heaven, the anointed King of God's kingdom and our Lord (1 Cor 8:6b). He is the ultimate Prophet foretold by God to Israel (Deut 18:18). He is the savior of the world, the only one to have lived a sinless life, and one whom God made the source of eternal salvation (Heb 5:8-9). He is furthermore the only human being to have been raised from the dead into immortal glory (Col 1:18, Rev 1:5) and is now sitting at the right hand of God with full honor and majesty (Ps 110:1). Surely this is a person who is not "merely" anything.
Despite these great honors, it is true that Christ is a man, and a man made "like his brothers in every way" (Heb 2:17). We are told that "he is not ashamed to call them brethren" (Heb 2:10-11); indeed, he consistently referred to his followers as "these brothers and sisters of mine" (Matt 25:40, Matt 12:50, Matt 28:10), and indicated that they would ultimately reign with him in his Kingdom (Luke 22:30, Rev 3:21, 2 Tim 2:12). It is because Christ has "taken the lead among" humanity that he is considered "the firstborn among many brothers and sisters" (Rom 8:29). If one holds that Jesus just is God however, then one must ultimately consider oneself a brother or sister to God, which seems to overstep the message of the New Testament.
The Apostle Paul adamantly taught that Jesus had to be a real human being in order to atone for our sins: "Therefore, he had to be made like his brethren in all things, so that he might become a merciful high priest in things pertaining to God, to make propitiation for the sins of the people" (Heb 2:17). Jesus perfectly fit the requirements of high priesthood precisely because he was a man: "Every high priest is a man chosen to represent other people in their dealings with God" (Heb 5:1).
Paul tells the Corinthian church, "For since death came through a man, the resurrection of the dead comes also through a man" (1 Cor 15:21) and again to the Romans, "through the disobedience of the one man the many were made sinners, so also through the obedience of the one man the many will be made righteous" (Rom 5:15,19). He also referred to Christ as "the last Adam," indicating a parallel to the first Adam; both were made in the image of God, both were created as sinless human beings. Of course, the first Adam made a mess of things, and the last Adam is fixing them even now--this is the underlying message from Paul.
"For there is one God and one mediator between God and mankind, the man Christ Jesus"- 1 TIM 2:5
Paul also explained that Christ, whom he calls "the man," is the appointed mediator between the one God and the rest of mankind (1 Tim 2:5). He furthermore informs us that God "has set a day when he will judge the world with justice by the man he has appointed" (Acts 17:31). These are only a fraction of the teachings we find in the New Testament declaring Christ's humanity.
Lastly, the Apostle John gave us a stark warning that "many deceivers, who do not acknowledge Jesus Christ as coming in the flesh, have gone out into the world. Any such person is the deceiver and the antichrist" (1 Jn 4:2-3, 2 Jn 1:7). In other words, Jesus is a real flesh-and-blood human being. If he was more than a human being, say an angel, or God, we would expect the Apostles to clearly teach these things, especially if such warnings were given about the dangers of getting it wrong. However, John does not speak of any inherent deity or dual-natures, but simply that Jesus was human. Given that there are no clear explanations of his being anything but human, we believe we have rightly taken the most biblical stance possible, that the Lord Jesus, the son of God, is and always has been a human being.
The above post was taken from here.
