Al-A'raf 7:157

To the knowledge of the Israelites, whatever prophets had come, had all without exception been from their own community. Now, according to God’s plan the last prophet was to be appointed from the Children of Isma‘il, a fact which God had already conveyed to the Israelites through their prophets. They were given these tidings, so that when the last prophet appeared, they should not have to undergo any great trial, but be able to recognize him readily and rally to his cause. Many predictions on this subject are still extant in their Books. The Prophet Muhammad was unlettered, so that no one might doubt his credibility. If he had been educated, people would have had their doubts that he had invented everything himself, while attributing it to God. Furthermore, according to Jewish tradition, it was predicted in the scriptures that the Final Prophet would be unlettered, so that people would have no difficulty in recognizing him as a prophet of God. The real spirit of religion is the fear of God and concern for the Hereafter. But in the later generations (of a prophet or a reformer) when the inner spirit became less ardent, and the utmost importance was attached to the form, the Prophet Muhammad brought the pure religion, free of all human additions and interpolations. When a prophet appears, the greatest virtue lies in believing in him. But this Faith does not simply mean reciting a few words as if performing a ritual. It, in fact, amounts to abandoning the soulless structure of rituals in favour of a living religion, having direct appeal to human nature. Man’s links with the former religious structure rest simply on the strength of historical traditions and racial customs. But when he accepts a new religion (of a new prophet) it involves a conscious decision on his part. He leaves behind him soulless rituals and opts for the reality. This appears to be a simple matter, but this has proved to be the most difficult step to take in every age. (That is, people find it most difficult to see beyond appearances).