How to debate! Explicit guidelines by Imam Ahmed Alhasan as

I wanted to advise you regarding the debates or dialogues with the ones who oppose us, please I ask you to not reject them; because through that we make the Da’wa reach the maximum possible number [of people]. And please I ask you to deal with the people and with your guests with good manners, especially with those who come to you and speak with good manners even if they were Wahabis, for you do not know perhaps Allah will do something later, how would you know for whom Allah has written guidance and for whom He has written misguidance.