﴿ وَمَا يَتَّبِعُ أَكْثَرُهُمْ إِلَّا ظَنًّا ۚ إِنَّ ٱلظَّنَّ لَا يُغْنِى مِنَ ٱلْحَقِّ شَيْـًٔا ۚ إِنَّ ٱللَّهَ عَلِيمٌۢ بِمَا يَفْعَلُونَ ﴾

“For, most of them follow nothing but conjecture: [and,] behold, conjecture can never be a substitute for truth. Verily, God has full knowledge of all that they do.”

(Most of them follow) worship (naught but conjecture) i.e. except through conjecture. (Assuredly conjecture) their worship through conjecture (can by no means take the place of truth) can by no means dispense them from Allah's chastisement. (Lo! Allah is Aware of what they do) in their state of idolatry, in terms of worshipping idols, and other things.