Abu said al-Khudri radiallahu anhu said:
I heard the Messenger of Allah may Allah bless him and grant him peace say: If any one you see something objectionable, he should change it with his hand if he can change it with his hand. But if he cannot (do so), he should do it with his tongue, and if he cannot (do so with) his tongue he should do it in his heart, that being the weakest form of faith.
The Prophet peace and blessings of Allah be upon him explains that the believer will be strong or weak in his faith, depending on the attitude of the believer to the deeds that are denied by Islam.