We’ve all been subjected to evangelical Trinitarian Christian material; the more you look into their claims the more you realize how far off the mark they are. The mere fact that there exists CHRISTIANS, who do not believe Jesus is God, is enough to spark further study of THEIR proof texts – the Bible. Here we can ponder upon the way evangelical Trinitarian Christians misuse the term ‘son of God’ whilst attempting to convince Muslims (and others) that a man (Prophet Jesus) is God Almighty.
The Jesus scholar, Geza Vermes, lifts the lid on the term 'Son of God' and what it actually means rather than the stuff churned out by evangelical Trinitarian Christians.
Common knowledge: ‘Son of god’ is figurative not literal
It is common knowledge that before the New Testament, the Hebrew Bible and the Dead Sea Scrolls regularly speak of ‘Sons of God’ and occasionally refer to God in figurative speech as ‘begetting’ or ‘procreating’ a human being. 
‘Son of God’ used for ANY Jewish male who was pious
In the Bible and in writings produced during the centuries that followed the completion of the Old Testament, ‘Son of God’ occurs in a variety of meanings. In addition to the angels already discussed, among the humans ‘Son of God’ was the title of anyone believed in some way to be linked to God. Every male Israelite could pride himself on being a ‘son of God’, and reciprocally he was in a position to call God his Father. In the course of time the phrase was also applied – more and more restrictively – to the good Jews, to the especially holy Jews, culminating with the king of the Jews and finally with the Messiah, the most holy and powerful future ruler of Israel about whom we read in the Florilegium, one of the Dead Sea Scrolls, ‘I will be his Father and he shall be my Son. He is the Branch of David’ 
‘Son of God’ NEVER referred to a ‘man god’
Trinitarian Christians who promote Jesus to the status of God are found wanting with regards to the basic term ‘son of God’ as the scholar confirms the term does not refer to their idea of Jesus.
…It is universally agreed among experts that in Judaism the phrase [‘Son of God’] is always used metaphorically; it never designates a person who is believed to be simultaneously man and God, a human being who also shares in some way divine nature. 
Christian misinterpretation of Psalms
Here is another important point to be aware of whilst dialoguing with Trinitarian Christians, you may have come across some Christian missionaries citing Psalm 2:7 whilst proclaiming it as a verse denoting deity of Jesus; however, the Jesus scholar – Geza Vermes – highlights their misinterpretation
The Jewish king, while the monarchy existed down to 586 BC, and the awaited royal Messiah after the Babylonian exile, were systematically portrayed as engendered by the Deity: You are my son, today I have begotten you’, we read in Psalm 2:7 
 The Nativity, Geza Vermes, Penguin, 2006. p53 and 54
 Ibid. p54
 Ibid. p54
 Ibid. p54