What are the nullifiers of righteous deeds?

Among the nullifiers of deeds are disbelief (kufr) and showing off (riya'). Disbelief nullifies deeds, as stated in His Almighty's saying: "And whoever disbelieves in faith—then his work has become worthless, and in the Hereafter he will be among the losers" (Quran 5:5). Showing off renders deeds as scattered dust, as mentioned in the Qudsi Hadith: "I am the most self-sufficient of partners, having no need of a partner. He who does a deed in which he associates another with Me, I abandon him and his association." Also among the nullifiers of deeds is a servant’s outward display of righteousness before people while violating Allah's sacred limits when alone.