Some young people use harsh and cruel methods when trying to guide people, debate with them and call them to give up what is contrary to Sharia. They think that being harsh will give results and deter people, but they forget that being kind and gentle is the original principle that is not to be forsaken until after all gentle and kind means have been exhausted. Gentleness is what yields good results and has an impact on people’s hearts; harshness, on the other hand, puts people off in most cases and makes the transgressor persist in his ways.
It is very strange that these people did not differentiate between the one who transgresses the limit knowingly and the one who does so unknowingly; between the one who promotes innovation and the duped, misguided victim; and between mistakes concerning which there is a difference of scholarly opinion and mistakes on which there is consensus that they are wrong….
They forget that their harsh treatment and refraining from helping deepens the gap between them and people and causes people to go and join the ranks of the deviants who are the enemies of Islam…
Islam’s stance on violence and harshness when calling to Islam and interacting with people is very clear. Allah (swt) says, enjoining Moosa and his brother Haroon:
“Go, both of you, to Fir’aun [Pharaoh], verily, he has transgressed [all bounds in disbelief and disobedience and behaved as an arrogant and as a tyrant]. And speak to him mildly; perhaps he may accept admonition or fear [Allah].” [20: 43-44]
These were the instructions of our Lord (swt) to Moosa and Haroon (as) when calling the tyrant Pharaoh: to speak mildly or gently when explaining the truth because it is more beneficial and more likely to be accepted and to instil fear of Allah (swt).
[Taken from "The Life And Times Of 'Alee Ibn Abee Taalib" by 'Alee Muhammad As-Sallaabee, p. 309. See also, "Dhaahirat Al-Ghulw Fid-Deen", Pp. 231-237]