“But after he had considered this, an angel of the Lord appeared to him in a dream and said, ‘Joseph son of David, do not be afraid to take Mary home as your wife, because what is conceived in her is from the Holy Spirit’” Matthew 1:20
“The angel answered, ‘The Holy Spirit will come upon you, and the power of the Most High will overshadow you. So the holy one to be born will be called the Son of God’” Luke 1:35
Luke 1:35 calls Jesus “the holy one,” meaning that he will be born without any taint of sin. Virgin-born, Jesus has no inherited sin from Adam, no sin nature, nothing in him that will cause him to sin. He is holy in the truest and deepest meaning of that term.
He is fully human because he comes forth from Mary’s womb. He is fully divine because he is conceived by the Holy Spirit. He is not half-human and half-divine. He is the God-man—one person possessing two natures, God incarnate in human flesh.