Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates that the Prophet Muhammad (peace and blessings be upon him) said: "Hasten to do (good) deeds before the coming of tribulations which will be like pieces of a dark night, in which a man will be a believer in the morning and a disbeliever in the evening, or a disbeliever in the morning and a believer in the evening. He will sell his religion for the goods of this world."