Jesus never called himself Son of God. Jesus always called himself "Son of Man". This is based on the four main Gospels of the new testament accepted by the Church.
Many who claim that Jesus was God unlike any other man usually quote the transfiguration and the other incident where his forgave someone for his sins. Jesus was also quoted saying Jesus that he and the Father is One. To ordinary humans, theologians and the modern Church, this implied that Jesus is God, unlike any other human being.
In fact this was the big debate by the early Christian elders in the Council of Nicea in 325 AD. One side proposed Jesus is God and the other proposed that Jesus was a human who reached the highest spiritual state a human can get.
The side that supported that Jesus was God won the debate, while the side that lost was hunted down a killed cruelly as heretics. After that many books and other less known Gospels that was not consistent with Church's viewpoint were banned and destroyed. The Christians today embrace the viewpoints of those who won the debate at Nicea.
My search for the truth reveals that the truth lies with those who lost the debate and were killed and persecuted for what they believe in.
Even if everything in the four Gospels are right, the losing side can be right. Because nothing in those Gospels says that Jesus was the only son of God. There is more evidence to suggest we are all "sons" and "daughters" of God. Jesus is one of the few human who realized that he was the "son" of God. The Nicean Creed which is imposed by the Church states that Jesus is the only son of God which I believe is false.
In reality God is not a parent. He is neither male or female.
But there is no word in human language to accurately label our relationship with God. The closest would be "sons" or " "daughters" of God, but this is not accurate.
Many may feel that I have betrayed Jesus and today's Christianity. But ask yourself does Christ prefer that you know the truth about him or the falsely imposed statement about him. Jesus will appreciate that you know truth about him.