Hazrat Moulana Ashraf Ali Thanwi (rahmatullahi ‘alaih) once mentioned:

Nowadays we find a common sickness prevalent everywhere, that most people are worried about the faults and weaknesses of others, but do not pay any attention to their own weaknesses and inner maladies (whereas we are commanded in sharee’ah to be more concerned about our own islaah

[reformation]). If only each person could focus on his own weaknesses and correct himself, he will save himself from a great amount of problems and difficulties. (Malfoozaat Hakeemul Ummat 6/399)

Source: Ihyaauddeen.co.za