Q 2: Is Iman (Faith) a whole which can never be divided? When a part of it is lost, is the rest lost too? If this is true, how can we reconcile between this claim and the fact that (Part No. 2; Page No. 435)
Iman is subject to increase and decrease?
Iman is divisible, as it increases and decreases. Allah (Exalted be He) says:
...And when His Verses (this Qur’ân) are recited unto them, they (i.e. the Verses) increase their Faith; and they put their trust in their Lord (Alone).
Allah (Exalted be He) also says:
And Allâh increases in guidance those who walk aright.
Loosing some of your Iman does not mean losing all of it; because the opinion that inclines to the loss of all of one's Iman due to the loss of part of it is the doctrine of
Al-Khawarij (separatist group that believes committing a major sin amounts to disbelief). Verily, it is an incorrect opinion because Allah (Exalted be He) says:
And if two parties or groups among the believers fall to fighting...
Here, He describes them both as believers even though there is a fight between them. Allah (Exalted be He) also says:
But whoever overlooks (and pardons) from his brother (i.e. The murderer) anything, then there should be a suitable follow-up and payment to him (i.e. To the deceased’s heir or legal representative) with good conduct.
Here, Allah (Exalted be He) calls him a brother even though he is a killer.The doctrine of Ahl-ul-Sunnah (those adhering to the Sunnah) is that a person can combine both Iman and Fisq (flagrant violation of Islamic law) and obedience and disobedience; as Iman increases with obedience and decreases with disobedience. (Part No. 2; Page No. 436) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.