Translation of the meanings Ayah 7 Surah Al-Kahf - English Translation - Abdullah Hasan Yaqoub - The Noble Qur'an Encyclopedia

Ayah: 7

إِنَّا جَعَلۡنَا مَا عَلَى ٱلۡأَرۡضِ زِينَةٗ لَّهَا لِنَبۡلُوَهُمۡ أَيُّهُمۡ أَحۡسَنُ عَمَلٗا

7. Indeed, We have made whatever is on earth as an adornment for it, so that We may test them as to which of them is best in conduct and deed⁴.

4. This world is the place of striving and the Hereafter is the place of reward or punishment, where the believers will be rewarded with Paradise and the disbelievers will be punished with Hell. 
Paradise is good and none but those who are good will enter it. Allāh is Good and accepts nothing but that which is good. So the way of Allāh with the people is to test them with calamities and tribulations, so that the believer may be known from the unbeliever and so that the truthful may be distinguished from the liar.