Abu Hurairah narrated that the Messenger of Allah(s.a.w) said:
"Rush to do good deeds. A Fitnah will occur that is like a portion of the dark night, morning will come upon a man as a believer, who will be a disbeliever in the evening, and evening will come upon a believer, who will be a disbeliever in the morning. One of them will sell his religion for goods of the world."