EVERY religion in the world has got different factions in it, for example Sunni muslims comprise around 90% of muslims, yet Shiite muslims don't regard Sunnis as true muslims.
So who are the true muslims Shiites or Sunnis?
As regards Catholics, they've got some wacky ideas but at least they regard Jesus as the Son of God..
in islam, the criteria for being muslim is
1) to believe in Allah
2) to believe prophet Mohammad is God's final messenger.
obv within that there are more beliefs eg
'belief in the day of judgement, in angels, heaven and hell etc'.
The shia have always regarded sunnis as muslims. The key issue is that in recent times, the wahabi sect from saudi arabia born of arab supremacism, nationalism and pseudo islamic revivalism has attacked the shia. The wahabis are worse than the sadducee's in the time of Jesus. Don't breath, they'll accuse you of kufr and bidah (religious innovation).
so really once again you tried to make a point about islam without any research or truth to it.
you don't believe the 'Son of God' is God/co-equal in Godhead with the Father. you also know that the holy spirit is not greater than the son..
so you obv reject the trinitarian doctrine.
why don't you just be sensible and accept that the term 'son of God' was not meant to be literal, but symbolic?
you didnt know who philo was for example. philo was 20 yrs older than Jesus. He actually was the guy who introduced the greek term 'logos' and merged it with the 'Image of God' before giving it a new symbolic judaic name (so that it would be easier for jews to accept), hence 'the only begotten son of God'.
as i said, the term 'ben elohim' has already been used in the OT..even the demons were called 'sons of God' in the OT.