Having knowledge of the nullifiers of worship is from the greatest means of safety from falling into those actions which diminish (an act of worship’s reward), or nullify it entirely. For example, knowledge of the nullifiers of wudoo, no Muslim has any doubts about it’s importance, because whoever does not know the nullifiers of wudoo, it is possibly he could nullify it and then prays (without it), and his prayer would be invalid due to the hadeeth,
There is no prayer for the one who has no wudoo.” (1)
(In conclusion) knowledge of the nullifiers of Islam are greater and more important than knowledge of the nullifiers of wudoo, because whoever nullifies his Islam, then no action is excepted from him, even if his action benefits the people. Therefore knowledge of the nullifiers of Islam is a must, as is studying these nullifiers and reviewing them in light of the Quran and the Sunnah, and understanding them and then seeking Allah’s Aid in not falling into them.
Shaykh Muhammad Amaan Al-Jaami’s (rahimahullah) Explanation of The Nullifiers of Islam by Shaykul Islam Muhammad ibn Abdul Wahhaab (rahimahullah)
(1) Sunan Abu Dawood 101, Authenticated by Shaykh Al-Albaani