Jesus called Himself the Son of Man as well as the Son of God. The first name emphasized His humanity and the second emphasized His deity. He was not a Son of God but the Son of God.
Jesus, Son of God
The fact that Jesus is the Son of God can be a hard truth to understand. Our human minds can not easily grasp the actuality of this truth. This is why faith is required.
Jesus life from its very conception was God given. He was born from a virgin, a woman chosen by God to carry His Son.
The Holy Spirit will come on 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
This tells clearly how Jesus was conceived and why He was called the Son of God. This is also revealed in the prophecies in Isaiah as are all of the others.
No one can explain the purpose better than Billy Graham. In his book , Peace with God, he explains the purpose behind God becoming flesh.
“… He came to reveal God to men. He told us that God loves us and is interested in our lives. He told us of the mercy and long-suffering and grace of God. He promised life everlasting.
“But more than that, Jesus Christ partook of flesh and blood in order that He might die. … The very purpose of Christ’s coming into the world was that He might offer up His life as a sacrifice for the sins of men. He came to die.
“… Every word that He spoke was historically true. Every word that He spoke was scientifically true. Every word that He spoke was ethically true. There were no loopholes in the moral conceptions and statements of Jesus Christ.”—Billy Graham, Peace With God © 1984, Billy Graham
Out of all of the names that have been used for Jesus, I would say that Son of God is the most amazing one. It is the one that clearly states what He is and no real translation is necessary.
To read the entire series
12 Names of Jesus, click HERE.