I happened to watch a video by a Muslim apologist. He claims that the Comforter mentioned in the Bible [in John 14] is Muhammad, and that he is also mentioned in Song of Solomon. How should I respond? -- David 

First of all, the Comforter to come in John is the Spirit, not the prophet Muhammad. This is clear when we read the passage in its entirety -- that is, in context. Anyone can pluck out a few words that seem to relate to one subject, while in fact they are wholly unrelated. So let's go to the passage in question.

At the end of his ministry, and his training of his disciples, Jesus said, “All this I have spoken while still with you. But the Advocate [or Counselor; Greek paráklētos], the Holy Spirit, whom the Father will send in my name, will teach you all things and will remind you of everything I have said to you" (John 14:25-26).

Context
These words were spoken on the night of his arrest. The context is the training of the Twelve, not a prophet utterance to be fulfilled some 600 years later! Key dates: Jesus died and rose in 30; Muhammad began to receive messages from Gabriel (so it is claimed) in 610 AD. Jesus encourages the disciples with the knowledge that their training will continue; the Spirit will comfort and advise and strengthen them. The Spirit will assist them in their leadership and doctrine in three directions: with reference to the past (what he has taught them, some of which they might forget); in the present (ongoing teaching); and in respect to the future (what is yet to come). There is nothing here both another human teacher, let alone an Arabian prophet. The comfort Jesus promises is at hand -- not six centuries distant!

Notice also that the Comforter is to come in Jesus' name. No Muslim will agree that Muhammad came in the name of Jesus!

But there's more. Jesus' words on the night of his arrest continue: 

“I have much more to say to you, more than you can now bear. But when he, the Spirit of truth, comes, he will guide you into all the truth. He will not speak on his own; he will speak only what he hears, and he will tell you what is yet to come. He will glorify me because it is from me that he will receive what he will make known to you. All that belongs to the Father is mine. That is why I said the Spirit will receive from me what he will make known to you" (John 16:12-15).

It is abundantly clear that Jesus is referring to the Holy Spirit, not to Muhammad. Moreover, Jesus assured his disciples that the Spirit would come soon (Acts 1:5; see also Luke 24:49) -- not in 600 years!

Corruption?
Now Muslim scholars may well claim the biblical text has been corrupted. The problem is that all manuscripts of John before the time of Muhammad agree in their wording. When did the message suffer degradation? Not in the 3rd or 4th century, since complete manuscripts of John date from this time, and they agree on the identity of the Comforter. In the 1st or 2nd century? With John dying around the turn of the century, this means his own gospel would have had to become hopelessly perverted during his own lifetime, or that of his successors! This would also mean that Jesus failed to train the apostles, for their message was abandoned in their own lifetimes, right under their noses!

Islamic teachers frequently claim that the "counselor" has been mistranslated. But if so, their entire apologetic point about Muhammad being prophesied in John vanishes! At any rate, this is their reasoning. Muhammad means "praised one." Paráklētos (counselor, comforter), the word in John 14 is similar to períkleitos (famous all round, renowned). But there is a complete lack of manuscript evidence -- no variant exists -- to suggest that Jesus said "the praised / renowned one," as opposed to "the comforter."

One final consideration: The role of the comforter is to enable the apostles (us too, through their work) to remember what Jesus taught. Does Muhammad help us remember what Jesus taught, for example, that Jesus came from heaven (John 3:13)? Not at all. There is no improvement on Jesus' message, or recollection of authentic words or events. (The Qur'an does, however, cite the N.T. apocrypha, fanciful tales told about Christ in later centuries.) If the prophet really helps us to live by Jesus' words, why does he allow one to smite his enemies, whereas Jesus had us turning the other cheek? Jesus claimed divinity (John 14:9; Mark 14:62; see Dan 7:13-14; Ps 110:1).

Muhammad in Song?
As for Muhammad being mentioned in Song of Songs 5, the Hebrew consonants in question are not a personal name (a proper noun). The prophet appears nowhere in the Song. Here is the passage in question:]

"His mouth is sweetness itself;
    he is altogether lovely.
This is my beloved, this is my friend,
    daughters of Jerusalem" (Song 5:16 NIV).

Compare to the more literal rendering of the New American Standard Bible:

“His mouth is full of sweetness.
And he is wholly desirable.
This is my beloved and this is my friend,
O daughters of Jerusalem” (Song 5:16 NASB).

The constants (mHmdym) may remind some Hebrew readers of Muhammad (especially if they are also Arabic speakers), but the claim is an incredible stretch. Incredible not in the sense of being amazing, but in being impossible to believe or take seriously. For more on Song 5, see the excellent material at Answering Islam. 

Conclusion and a Challenge for Christians
Despite efforts to locate Muhammad in the Bible, he is not there. And we were forewarned about so-called, self-styled prophets who would come and attempt to undo the work of Jesus and his apostles (Gal 1:6-9; 2 Pet 3:1-3; 1 John 4:1; and many other verses).

Because Muslim apologists nearly always take biblical passages out of context, it is usually quite simple to respond. Of course the challenge to interpret texts in context isn't only a warning for outsiders; Christians too must learn to do this, and far too many believers find what they are determined to find in the Bible by plucking phrases and sentences our of their contexts and pressing them into service to justify their position. This is important, because in all things, Christian men and women are to model integrity -- and we either read the scriptures with integrity or without it.