Prophet Muhammad (salallahu alihi wa sallam) said : "
The most hated speech to Allah is when a man says to another man, 'Fear Allah!' and he replies, 'Worry about your own self!' "
[It was reported by Al-Asbahaanee in At-Targheeb (#739), and Sheikh Albani authenticated it in Silsilatul-Ahaadeethis-Saheehah (#2598)].