The Prophet ﷺ said, "There are three qualities by which a person finds the sweetness of faith. That Allah and His Messenger are more beloved to him than anything else, that he loves a person solely for the sake of Allah, and that he hates to return to disbelief just as he hates to be thrown into the fire."
عن النبي ﷺ قال: ثلاث من كن فيه وجد حلاوة الإيمان: أن يكون الله ورسوله أحب إليه مما سواهما، وأن يحب المرء لا يحبه إلا الله، وأن يكره أن يعود إلى الكفر كما يكره أن يقذف في النار.
Bukhari narrated it in the Book of Iman (16), and Muslim narrated it in the Book of Iman (43), both from the hadith of Abdul-Wahhab Thaqafi, who said, Ayub narrated to us, from Abu Qilaba, from Anas, and he mentioned it.Muslim also narrated it through another route, from Hammad, from Thabit, from Anas, who said, the Messenger of Allah ﷺ said something similar to their hadith, except that in it he said, "than to return to being a Jew or a Christian."