Being learned at theology, religion sciences, Semististik, and Indologie at the University of Marburg from 1966 to 1973, he became a famous German Orientalist. Many experiences he had within 1976 to 2000. In 1981, he was academic advice at the University of Nuremberg. Then in 1992 he attained a Professor for Islamic Studies after he proved his capabilities with giving training in area Semitic philology and Islamic Science since 1986.
The article he wrote aims to seek another understanding with the meaning of the seal of Prophets (khatam an-nabiyyin). As widely known, khatam an-nabiyyin merely carries a meaning of there is no Prophet will come after him (Muhammad PBUH). Yet the fact that ‘Prophetic’ movement within Islam has arisen again and again as Allah said in Q.S: 3.144 (Muhammad is not but a Messenger. [Other] Messengers have passed on before him). In other words, what he tries to do is to make Muslim thinking that the meaning of khatam an-nabiyyin also can have another meanings; and that would be a form of continuity (as he suggests).
To pursue its goal, he firstly begun to compare the way Qur’an mentioned Muhammad’s Prophetic to Arabs with the way the Book of Daniel (Sacred Kitab of Jews) mentioned Jesus’ to Christians. At a glance, it logically would be the same. Jesus came after Moses, and Muhammad came after Jesus. As well Moses was shown as the leader of the ‘Children of Israel’ (banu Israil), Jesus as the leader of the Christians (Nasara) and Muhammad as the leader of Arab. Those facts slightly bring our mind to say ‘yes’ to this article’s aim. Anyway, he already admitted that attempt to understand the nature of Muhammad’s prophethood on the basis of biblical precedent is a questionable method.
Secondly, he presents all the characters of Muhammad that are mentioned in Quran, such as ‘warner’ (Nadhir, mundhir; cf. Q51: 50.51, Q79: 45), ‘bearer of good news’ (bashir or mubashir; see Q 35: 24). Also the virtues demanded to Muhammad toward his God; such as ṣabr (steadfastness, patience) or tawakkul (faith in God), or call on him to leave matters to God (dharnī, cf. Q 68:44). He said, these characters show a clear resemblance to that of piety found in Syriac Christian monasticism. Thirdly, because Muhammad PBUH was habibullah, he matches the notion of “God’s chosen one” to those 25 Prophets mentioned by Quran. The result was profound. All the “family of Abraham,” the “Children of Israel,” and the “family of ʿImrān,” which correspond to the Jewish patriarchs or pre-Mosaic Jewry (= āl Ibrāhīm), Mosaic Jewry (banū Isrāʾīl), and post-Mosaic Jewry together with Christians and Jewish-Christians (= āl ʿImrān).
All these three methods have proven the similarity of Muhammad’s, Moses’ dan Jesus’ prophethood. However, I personally disagree on that finding. Because it would open up opportunities for the Jews and Christians defend their faith, whereas the Prophet Muhammad was sent enhancing the teaching of previous Prophets. At the end of the world Prophet Isa was sent, instead bringing a new doctrine, but rather to defend the teachings of the Prophet Muhammad from the Quran and Hadith. To support my opinion, I’ll attach one prophetic tradition. The chain of Messenger and Prophets has come to an end. There shall be neither Messenger nor Prophet after me. (Tirmidzi, Musnad Ahmad, Anas bin Malik).