The majority of those who claim to believe in Allah, practically submit to false authorities; humans and idols in countless forms. That is indeed SHIRK and they are MUSHRIKOON
As a result most of them who believe in Allah also commit shirk
Dr. Munir Munshey
Most of them do believe in Allah, but then they associate partners with Him
Dr. Kamal Omar
And the majority of them believe not in Allah except that they attribute partners [in His Dominion (in their concepts, beliefs as well as practical deeds)]
As to those who believe in God, most of them believe in other (man-invented) gods (Christians believe that Jesus in God and most people fall so much in love with their women, wealth employer, etc. that they raise them to the heaven and start to worship them!
Faridul Haque
And most of them are such that they do not believe in Allah except while ascribing partners (to Him)
Hasan Al-Fatih Qaribullah
And most of them do not believe in Allah, but they associate others with Him