One reason for original Islam becoming alien is that as time went by self-styled interpretations of the Qur'an and Sunnah gradually placed a veil over the original content of these texts. A time came when the original Islam was completely obscured from view. The wrong, man-made interpretations took the place of revealed guidance. In later times, people mistakenly took the misconceptions in Islam to be the real Islam.
In the early phase of Islam people derived their religion directly from the Qur'an (the word of God) and Sunnah (the sayings and actions of the Prophet Muhammad), therefore, their association with the original Islam remained intact. But the interpretations and explanations of later days served only to obscure the original teachings. The natural beauty of Islam disappeared over the centuries. The Qur'an and Sunnah now turned into relics instead of being instruments of guidance. Thus the religion came to be based on latter-day interpretations and explanations instead of the original scriptures.
How did this corruption set in in the literature produced by the later generations? The answer is that certain people, having command over the language, were able to acquire a superficial knowledge of the scriptures but were unable to understand them in depth; for this, realization (ma'arifah) is required. When one finds religion at the level of realization, one is endowed by God with the wisdom (hikmat) to be able to understand the deeper meaning of the words of the scriptures. On the other hand those who are not blessed with this special gift of wisdom, have nothing by which to understand Islam, except their own pre-conceptions.
They begin to interpret religion according to their own mindset. The result is that, although they refer to the original sources of Islam - the Qur'an and Sunnah, their interpretations have little bearing on the original texts. Religious degeneration ensues in which they appear to follow Islam but actually stray far from its spirit. They fail to differentiate between God-sent religion and man-made interpretation.
One great loss created by these additions to the original Islam was the shift in emphasis. Some important teachings of Islam were relegated to the background-for instance, concern for the larger humanity, missionary work, patience, etc. Missionary work is the greatest mission of the Muslim Ummah, for, although prophethood came to an end with Prophet Muhammad, the mission of the prophet has not yet come to an end. The mission continues through the Ummah, as a matter of religious duty. It would be no exaggeration to say that without the performance of this duty, its very credibility of being the Muslim Ummah would become doubtful. Strangely, indeed, missionary work found no place in the literature of the centuries after the Prophet Muhammad. Neither has it been mentioned anywhere in the Muslim agenda of today. The classical commentaries of the Qur'an (Tafsir) also fail to give any prominence to missionary work as a concept. In books of Hadith (sayings of the Prophet) too, we find chapters on all subjects except missionary work. The same is true of Fiqh (Islamic jurisprudence) in whose texts we do not find a chapter on missionary work.
According to the Qur'an, the exercise of patience (sabr) is a deed, which makes man eligible for the highest reward (8:46); the patient man will be rewarded "beyond measure" (39:10). But the interpretation that gained popularity in later times was that the injunction of sabr, patience, had been abrogated and replaced by jihad (in the sense of qital, fighting). Thus, one who studies these books gathers the impression, that consciously or unconsciously, patience might have been important in the past, but nowadays it has lost its relevance. Now jihad (in the sense of qital) and not sabr is of foremost importance.
It follows that whenever they see the real Islam, it looks alien to them due to their conditioned thinking.
