Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Anas bin Malik (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Before the Day of Judgment, tribulations will appear like pieces of a dark night; a man will be a believer in the morning and a disbeliever in the evening, and a believer in the evening and a disbeliever in the morning. People will sell their religion for worldly goods."