Many Muslims and non-Muslims today believe that Sufism goes beyond Islam. Sufism or tasawwuf, as it is called in Arabic, is the inner dimension of Islam. Falling into sufism requires a teacher.
Among the oldest and most well known of the Sufi orders are the Sarwariyya, Qadri Al-Muntahi, Naqshbandi, Qadiri, Chisti, Oveyssi, Shadhili, Jerrahi, Ashrafi, Bektashi, and Nimatullahi. Sufism as a whole is mainly focused on direct personal experience (experiential learning). Classical Sufi scholars have defined Sufism as "a science whose objective is the reparation of the heart and turning it away from all else but God."
The ground of Sufism is Islam. Islam's holy book is Quran, which is often badly interpreted. The Quran, sura 47:4, states, "When you meet the unbelievers, strike off their heads; then when you have made wide slaughter among them, carefully tie up the remaining captives."
The above text can be also found on websites that criticize Islam, but the Bible, too, is not without similar statements, for example, in 1 Samuel 15, verse 2-3, it is written: 15:2 Thus saith the LORD of hosts, I remember that which Amalek did to Israel, how he laid wait for him in the way, when he came up from Egypt. 15:3 Now go and smite Amalek, and utterly destroy all that they have, and spare them not; but slay both man and woman, infant and suckling, ox and sheep, camel and ass.
Islam is a religion that respects Christ and some Muslims show even greater respect for Jesus than Christians.
Muslims believe that Islam is a continuation of the God's Revelation - that is, a continuation of Judaism (Old Testament) and Christianity (Old Testament and New Testament).
The word Sufi refers to "wool" and it probably also means humbleness of people who wear a simple cloak, which indicates the purity of ascetics. Sufis believe that they may get closer to God by certain techniques, which are, however, not available to the public. Sufism is a teacher-pupil based path and it also produced beautiful music and great musical masters like Nusrat Fateh Ali Khan.
This truthful religion is also mixed (in the Sunderbans region) into one God whom both Muslims and Hindus worship.