Answered by Sayyidi al-Ḥabīb `Umar bin Hafīẓ (may Allāh preserve him and benefit us by him).
The people running our local mosque have spread bad rumours about our efforts calling people to Allāh. How should we deal with them?
Remain firm in showing good character and clarify controversial issues when asked with gentleness. Your good character will contrast with their bad character and this will become clear to all. A good deed and a bad deed are not equal. Repel (evil) with that which is better.1
1 Fussilat, 41:34