Say, [O Muhammad], "Shall we [believers] inform you of the greatest..'

Say, [O Muhammad], "Shall we [believers] inform you of the greatest losers as to [their] deeds?
[They are] those whose effort is lost in worldly life, while they think that they are doing well in work."
Those are the ones who disbelieve in the verses of their Lord and in [their] meeting Him, so their deeds have become worthless; and We will not assign to them on the Day of Resurrection any weight [i.e., importance].