HSanAlim is right and I would like to add that there was sharp disagreement on who Jesus was among the Christians elders.
The losing side was forced to agree the Jesus was the only "Son of God". The term heresy was established by the wining side. The losing side was then hunted down and killed for what they believe in.
Because of the event, today's Christians were told by the Church, that Jesus was the only "Son of God".
My search reveals that God is not human or an animal to have off-springs. However, there is no word in the human language to describe our relationship with God. The closest would be "sons" and "daughters" even if this is not accurate.
Jesus was no more the "son" of God than we are. Jesus is one of the few humans who realized that man came from God. Jesus was not the only "child" of God. Like Jesus we all have the same relationship to God. This message of Christ to us was destroyed in 325 AD when the losing side fled for their life.
Jesus would appreciate if you know the truth about him.