The ruling on the nullification of deeds by shirk (associating partners with Allah) and kufr (disbelief)

Question:
And his saying in the hadith, "And did you preserve a deed?" Does preserving a deed mean preserving all deeds, so that it is like what was said about this fitnah (trial, discord or temptation) at the end, or is it preserved but not intended?

Answer:
This is possible, and Allah knows best. It is possible that it is a nullification of all deeds, and that his entry into the Fire will be eternal if he dies upon shirk (associating partners with Allah) or upon kufr (disbelief). And it is possible that it is a nullification of some deeds, and that his entry into the Fire will not be eternal because of the foundation of tawhid (the oneness of Allah) that he has. So, as we mentioned, this is according to what occupies the heart of the servant. If kufr (disbelief) or shirk (associating partners with Allah) occupies his heart, then this is an absolute, total nullification. And if something of shirk (associating partners with Allah) or something of minor kufr (disbelief) that does not take one out of the religion occupies his heart, then this is a partial nullification, not a total one.