Hadrat Ka’ab ibn Ayaaz R.A says that I heard Rasulullah Salallahu Alaihi Wasallam saying, “There is a Fitna for every Ummat (i.e. Allah Ta'ala tests every nation by putting them into some form of Fitna) and the Fitna (test) of my Ummat is wealth.

Allah Ta'ala blesses my Ummat with wealth in order to test them whether they will remain steadfast upon Deen when blessed with wealth or not!