Narrated by Anas bin Malik (Radi-Allahu ‘anhu):
The Prophet (Sallallahu ‘Alaihi Wa Sallam) said, “None will have the
sweetness (delight) of Faith (a) till he loves a person and loves him only
for Allah’s sake, (b) and till it becomes dearer to him to be thrown in the
fire than to revert to disbelief (Heathenism) after Allah has brought him
out of it, (c) and till Allah and His Apostle become dearer to him than
anything else.”
Bukhari Vol. 8 : No. 67
Sahih Bukhari Volume 8, Book 73, Hadith Number 67. – Hadith Collection