As to those who believe not in the Hereafter, We have made their deeds pleasing in their eyes; and so they wander about in distraction. Such are they for whom a grievous Penalty is (waiting); and in the Hereafter theirs will be the greatest loss. Q 27: 4-5

إِنّا جَعَلنا ما عَلَى الأَرضِ زينَةً لَها لِنَبلُوَهُم أَيُّهُم أَحسَنُ عَمَلًا
That which is on earth we have made but as a glittering show for the earth, in order that We may test them – as to which of them are best in conduct. Quran 18: 9