question #1 Sahih Muslim 117, Book 1, Hadith 219 : What is the significance of faith, even if it is as small as a grain or a dust particle, in the context of divine mercy and salvation?

Verily Allah would make a wind to blow from the side of the Yemen more delicate than silk and would spare none but cause him to die who, in the words of Abu ‘Alqama, has faith equal to the weight of a grain; while Abdul-‘Aziz said: having faith equal to the weight of a dust particle.