Refuting misconceptions about Islam is the duty of those who have knowledge
14-2-2015 | IslamWeb
Question:
As-salaamu 3laikum, I saw some Christian people on the Internet posting false criticisms and doubts about Islam. One Muslim said that one of them was spelling the name of the Prophet (salla Allahu 3laihi wa salam) in an offensive way but I was not sure if that was correct as I have seen a lot of different spellings in English and I don't know what the intention of the person was spelling it that way. However, I saw that no-one was responding to some of the arguments or some Muslims were responding but without knowledge and in an unclear way. I felt that I knew how to respond to some of their points as I had read about rulings on your website and on islamqa. So I responded to them with that information and added some of what I have seen myself of what you said about Christians directing some acts of worship to Maryam. I did not respond to all of their points nor did I mention anything about the spelling of the Prophet's name (salla Allahu 3laihi wa salam), not because I have any doubts about them being wrong, but only because I don't have enough knowledge on those points to give them a convincing answer, and I didn't find any statements of the scholars dealing directly with those points. Is what I did right or wrong? Jazaakum Allahu khair
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
May Allaah keep your reward. 
narrated that the Prophet, sallallaahu ‘alayhi wa sallam, said: "Fight (strive against) the polytheists with your wealth, your hands and your tongues." [Ahmad, Abu Daawood and An-Nasaa’i]
You were also correct to speak about what you knew and to keep silent about what you did not know. A Muslim is required not to speak about matters about which he does not have knowledge; Allaah says (what means): {And do not pursue that of which you have no knowledge. Indeed, the hearing, the sight and the heart – about all those [one] will be questioned.} [Quran 17:36]
Finally, we warn anyone who does not have enough knowledge of Islam to refute the misconceptions of such websites of disbelief and deviate against accessing them, for fear that he becomes confused about his religion and the misconceptions find a way into his heart and cause his destruction. For more benefit, please refer to Fatwa 91585.
Allaah Knows best.