According to the BIBLE, Jesus is God's Son.
There are many scriptures calling Jesus the 'Son OF God' or 'God's Son'. But significantly, Jesus is NEVER called 'God the Son'.
While the Father is always found in the Bible to be called "God", the phrase "God the Son" is never found. Further, if the Son really was God, then why would Jesus call his Father "the only true God"? (John 17:1-3)
Jesus is God's "only-begotten" son...the only being directly created by God. (John 1:18)
Jesus is "the beginning of the creation of God." (Rev. 3:14)
He is the "firstborn of all creation". (Col. 1:15)
Jesus is not God. Jesus is God's Son...the second most important person in the universe.
For more, see:
'Beginning,' 'Wisdom,' and 'Firstborn'