﴿ وَمِنَ ٱلنَّاسِ مَن يَقُولُ ءَامَنَّا بِٱللَّهِ وَبِٱلْيَوْمِ ٱلْءَاخِرِ وَمَا هُم بِمُؤْمِنِينَ ﴾

“And there are people who say, "We do believe in God and the Last Day," the while they do not [really] believe.”

(And of mankind are some who say: We believe in Allah), i.e. in the open and we are genuine in our belief, (and the last Day) and we believe in resurrection after death whereupon our deeds shall be requited, (when they believe not) i.e. secretly nor are they genuine in their belief.