Son of God

Why will Jesus “be called the Son of God” (Luke 1:35)?
Instead of being conceived between Mary and a man, Jesus will be born because “the Holy Spirit will come upon you, and the power of the Most High will overshadow you; therefore also, the Holy One to be born will be called the Son of God” (Luke 1:35).

Why did the angel say, “therefore also” (Luke 1:35) Jesus will be called the Son of God?
Jesus' resurrection will be another reason why He will be “declared the Son of God with power according to the Spirit of Holiness by the resurrection from the dead” (Romans 1:4). But the ultimate reason why Jesus is called the Son of God is that He always has been and will remain God the Son of God the Father (see My Father is Greater than I).

Didn't Jesus' existence begin in Mary's womb?
No, “in the beginning,” before the world was created, Jesus already “was God” (John 1:1), who is eternal: “from everlasting to everlasting You are God” (Psalm 90:2). Jesus entered humanity through Mary's womb to live a sinless life and then give His life to pay the death penalty due for our sins, but He never stopped being God. It should be noted that even though Jesus set aside His heavenly glory and divine power - He “emptied Himself, having taken the form of a slave, having been born in the likeness of men” (Philippians 2:7) - for the most part during His time on earth, He always had the option to take them up again, and occasionally did so: “And after six days, Jesus took Peter and James and his brother John, and led them up a high mountain by themselves. And He was transfigured in front of them. His face shone like the sun, and His clothes became white as the light” (Matthew 17:1-2). Also see Miracles of Jesus.

Was Jesus then half God and half human during His time on earth?
No, from Mary's womb until His ascension to heaven, Jesus was fully human, as demonstrated by the fact that He felt “thirst” (John 19:28), got “hungry” (Matthew 4:2, 21:18) and “tired” (John 4:6), and fully God, as demonstrated by His power over His creation - And having awakened, He rebuked the wind and said to the sea, “Silence! Be still!” And the wind ceased, and there was a great calm (Mark 4:39) - and by His power over death (see Lazarus, Come Forth and Resurrection of Jesus).

What was Jesus called until He entered humanity?
“Son of God” (Daniel 3:25), “God” (Isaiah 9:6), “LORD/YHWH” (Genesis 19:24), “Lord” (Psalm 110:1), “Word” (John 1:1), “Son of Man” (Daniel 7:13), etc. Also see “burning torch” in Genesis 15:17.