It is narrated from Hazrat Hudhaifa (may Allah be pleased with him) that in the blessed era of the Holy Prophet (peace and blessings be upon him), sometimes a person would utter a sentence and because of it become a hypocrite, and now in a single gathering I hear dozens of such words daily. You people should continue to enjoin good and forbid evil, otherwise Allah will inflict such a punishment upon you that you will pray to Allah but your prayers will not be accepted.
Hadith Referenceمسند احمد / مسند الأنصار رضي الله عنهم / 23312