Bismillahi ar-Rahmani ar-Rahim
Assalamu alaikum wa rahmatullahi wa barakatuhu
Christians often claim that their faith healing ministries have their foundation in the so called "Great Commission", where after his alleged resurrection, Jesus Christ (alaihi salam) commissioned his disciples to heal the sick in "his name". However, verses constituting the "Great Commission" do not appear in the earliest manuscripts. For example, the relevant part of Mark 16 is not found in the earliest Greek manuscripts of the New Testament (Codex Vaticanus and Codex Sinaiticus).
On the other hand, there are numerous foundations and justifications of faith healing found in Islam:
Uthman b. Abu al-'As Al-Thaqafi reported that he nade a complaint of pain to Allaah's Messenger (sallAllaahu alayhi wa sallam) that he felt in his body at the time he had become Muslim. Thereupon Allaah's Messenger (sallAllaahu alayhi wa sallam) said: Place your hand at the place where you feel pain in your body and say Bismillah (in the name of Allaah) three times and seven times A'udhu billahi wa qudratihi min sharri ma ajidu wa ukhdhiru (I seek refuge with Allaah and with His Power from the evil that I find and that I fear). (Sahih Muslim; Kitab-us-Salam)
Abu Sa'id Khudri reported that some persons amongst the Companions of Allaah's Messenger (sallAllaahu alayhi wa sallam) set out on a journey and they happened to pass by a tribe from the tribes of Arabia. They demanded hospitality from the members of that tribe, but they did not extend any hospitality to them. They said to them: Is there any incantator amongst you, at the chief of the tribe has bgen stung by a scorpion? A person amongst us said: 'Yes. So he came to him and he practised incan- tation with the help of Sura al-Fatiha and the person became all right. He was given a flock of sheep (as recompense), but he refused to accept that, saying: I shall make a mention of it to Allaah's Prophet (sallAllaahu alayhi wa sallam), and if he approves of it. then I shall accept it. So we came to Allaah's Prophet (sallAllaahu alayhi wa sallam) and made a mention of that to him and he (that person) said: Allaah's Messenger by Allaah, I did not practice incantation but with the help of Sura al-Fatiha of the Holy Book. He (the Prophet) smiled and said: How did you come to know that it can be used (as incactation)? - and then said: Take out of that and allocate a share for me along with your share. (Sahih Muslim; Kitab-us-Salam)
The Prophet used to treat some of his wives by passing his right hand over the place of ailment and used to say, "O Allah, the Lord of the people! Remove the trouble and heal the patient, for You are the healer. No healing is of any avail but Yours; healing that will leave behind no ailment." (Sahih al-Bukhari; Kitab-ut-Tiba)
There are numerous other examples, but these three ahadith should suffice to show the legitimacy of faith healing in Islam, in particular, Surah al-Fatiha, which is incidently also known as Surah ash-Shifa (the cure), is the mother of the Quran and is therefore also a means of faith healing when it is invoked.
Jazak Allah khair