10 Books Ahlul Bidah Wished That Were Never Written!
 Taqwiyatul Iman
Allamah Shah Muhammad Isma’il (1246H)
Shirk Will Never Be Forgiven.
Compiled and Translated
Abu Hibban & Abu Khuzaimah Ansaari
The Third Chapter
The Evilness of Shirk
Shirk (Polytheism) Will Never Be Forgiven
The First Sub-chapter in saving oneself from Shirk, meaning that this chapter is a summary of the evilness of Shirk
“Verily! Allah forgives not (the sin of) setting up partners in worship with Him, but He forgives whom He pleases, sins other than that, and whoever sets up partners in worship with Allah, has indeed strayed far away (Surah an-Nisa:l16)
From the ways of straying from path of Allah Is not to differentiate between the permissible and impermissible, being involved in stealing and fornication, abandoning the prayer and fasting, neglecting the rights of the wife and children and disrespecting ones parents. However the one who is engrossed in Shirk is the most naivest of individuals because he has involved himself in such a great and tremendous sin that Allah will never forgive it, however, Allah may even forgive all of his other sins.
This, we find from this ayah that shirk will never be forgiven and the punishment that is decreed for it will be surely direly incumbent. If the shirk is extreme (ie major) such that it leads a person to be a disbeliever, he will be punished such that he will remain if the fire of Hell forever, he will never leave it and nor will he ever experience any comfort therein.
(Note of clarity the Imam here means and is referring to Shirk Akbar and Shirk Asghar, however the ayah is clear and no matter what level the shirk is, the punishment will remain the same as per the verse, this is the explanation of Shaikh Ataullah Hanif Bhojiyani)
From the shirk that is of a lesser level (ie minor shirk) he will be punished according to that which Allah has decreed. With regards to other sins, some of the punishments have already been ordained by Allah, hence the affair is with Allah, whether he choses to punish or to forgive.
Taqwiyatul Iman (pg.34)