The Prophet ﷺ said, "There are three qualities, whoever possesses them will taste 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 would hate 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 في الكفر كما يكره أن يقذف في النار.
Bukhari related it in the Book of Faith (16), and Muslim in the Book of Faith (43:67), both through Abdul-Wahhab Thaqafi, who said, "Ayub narrated to us, from Abu Qilaba, from Anas bin Malik," and he mentioned it.