There are some people who worship Allah standing on the verge of faith (half faith and half disbelief). When such a person is blessed with good fortune he is content; but if they are afflicted with a trial, he turns back on his face (i.e. reverts back to disbelief). He loses both this world and the Hereafter. That is ˹truly˺ the clearest loss.
Meaning:-
Verge: an edge or border.
Content: in a state of peaceful happiness.
Afflicted: to cause suffering, pain, illness, disaster, trouble greatly or grievously