Muslims believe that one of the most important features of Jesus' mission was to give the 'glad tidings' of the coming of the Prophet Muhammad. During his short missionary career that lasted not more than three years, and which was overshadowed by the hostile attitude of his own people, Jesus gave them the good news of Ahmad, the last messenger of God, who would perfect the divine teaching both in theory and in practice. According to the Quran, Jesus said:
"O Children of Israel! I am the apostle of God (sent) to you, confirming the Law (which came) before me, and giving glad tidings of an apostle to come after me, whose name shall be Ahmad."(Surah 61:6)
Muhammad or Ahmad
The official Quran gives the name as Ahmad but there was a variant reading in the mashaf of Ubayy b. Ka'b who was one of Muhammad's secretaries. This rendering referred to a prophet after Jesus but did not speak of Ahmad (A. Jeffrey, Materials for the history of the text of the Quran, p.170). Furthermore we do not find any mention of the name Ahmad in Ibn Ishaq or Ibn Hisham's Sirah Rasul, in their discussion of the prophecy of the coming of a prophet after Jesus. (Alfred Guillaume, The Life of Muhammad, pp. 103-104). W. M. Watt says that "Muslim children were practically never called Ahmad before the year 125 A.H." (As quoted by G. Parrinder, Jesus in the Quran, p.99).
Abdullah Yusaf Ali in his translation of the Quran states, "Ahmad or Muhammad, the Praised One is almost a translation of the Greek word Periclytos. In the present gospel of John 14:16, 15:26 and 16:7, the Greek word Paracletos is translated in the NIV as Comforter. However, Paracletos means Advocate, one called to the help of another, a kind friend, rather than Comforter." Ali then claims, 'Our doctors contend that Paracletos is a correct reading for Periclytos, and that in their original saying of Jesus there was a prophecy of our holy prophet Ahmad by name' (The Holy Qur'an, English translation of the meanings and commentary, footnote 5438, p. 1461).
A Biblical response
Like Ali, many Muslims, when they do not find what they want to prove from the Bible, accuse the text of corruption. The same is the case here. The assertion that the original word in the Gospel of John was ‘paracletos’ so as to translate it ‘Ahmad’ in Arabic (the ‘praised one’) is baseless. No such documentary evidence exists to support this claim. There are a lot of New Testament manuscripts pre-dating Islam and not one of these contains such a variant reading suggested by Ali and others.
Another interesting point ignored by Muslim friends is that if Muhammad is accepted as Paracletos, it will contradict the Qur’an too. Ali translates the word also as ‘Advocate’. In Arabic this word is ‘wakil’. The Qur’an denies Muhammad being wakil. In fact according to the Qur’an, God asked Muhammad to tell people that he was not a wakil for them (Sura 6:66; 10:108).
In the Gospel according to John, Jesus promised the Paraclete four times (John 14:16; 14:26; 15:26; 16:7). Christians believe that the promise is about the Holy Spirit, who was to descend upon the disciples on the Day of the Pentecost (Acts 2), to witness to Christ and lead them into the whole truth and to be with the believers forever. The promise was fulfilled in the lives of the first disciples, so the idea of a fulfilment 600 years later in Muhammad would make it too late for them. Secondly, this Paraclete, comforter or the Spirit of truth, was going to live for ever while the Prophet of Islam only lived on this earth for about 63 years. Thirdly, Christians argue that the message the Paraclete was to give was from Jesus; "he will take it from me and will give it to you". If we were to agree with the claim made by Muslims, 'Muhammad being the Paraclete', then they would have to admit that the Quran came from Jesus.
A video on this subject with a few more points.