It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Hasten to do good deeds (before) trials (come) that will be like pieces of the dark night (covering everything). In them a man will be a Muslim in the morning and a disbeliever by the evening, and a Muslim in the evening and a disbeliever by the morning; he will sell his religion for a small amount of worldly goods."
Hadith Referenceالمعجم الأوسط / باب الميم / 8789
Hadith Takhrij«أخرجه مسلم فى «صحيحه» برقم: 118، وابن حبان فى «صحيحه» برقم: 6704، والترمذي فى «جامعه» برقم: 2195، وأحمد فى «مسنده» برقم: 8145، 8970، 10923، وأبو يعلى فى «مسنده» برقم: 6515، والطبراني فى «الأوسط» برقم: 2774»