کُونُوا دُعاةَ النّاسِ إلَی الْخَیْرِ بِغَیْرِ ألْسِنَتِکُم، لِیَرَوا مِنْکُمُ الإجْتِهَادَ وَالصِّدْقَ وَالْوَرعَ. Call people to righteousness through means other than your tongues so that they may observe diligence, truthfulness and piety in your actions.
Mishkat al-Anwar, page 30
Imam Ja'far ibn Muhammad al-Sadiq (peace be upon him)Hadith