I've merged several of your questions together, since they all seem to be referring to the same thing. That way I can address them all at once. For future reference, if you are asking a question for a specific worldview on this website, such as Christianity, please make certain to select that worldview in the drop down list on the ASK A QUESTION page, so that the wrong people are not asked the intended question. Thanks for your care in this.
The questions compiled together above all relate to whether or not Deuteronomy 18:18 is a reference to Muhammad, the Muslim prophet. These questions are in response to my answer to an earlier question entitled, "Do you deny that Deuteronomy 18:18-19 is speaking about Prophet Muhammad?".
First, the questioner is quite right that the word "countrymen" (found in the NASB) is not the necessary English translation of the Hebrew word used, although it is an acceptable one. "Brethren" is also acceptable. As the questioner may have already noticed, I have in fact updated my earlier answer to account for this. However, the point I originally made remains. Moses said the prophet would come from among the people he was speaking to (Deuteronomy 18:15 - KJV: "from the midst of thee"). To my knowledge, there is no claim among Muslims that Muhammad came from that group of people -- the ones brought out of slavery in Egypt by God through His servant Moses. However, as I pointed out in my earlier response, Jesus did come from them (Luke 3:23-38; Matthew 1:1-16).
Thus, all three of my original objections to applying this verse to Muhammad remain:
1. The future prophet would come from among the group of people to whom Moses was speaking. Jesus did. Muhammad did not.
2. The future prophet would be a prophet of God. Jesus was. Muhammad was not.
3. The apostle Peter tells us in the Book of Acts, chapter 3, that the prophet Moses referred to was Jesus. Muhammad is not Jesus.
So why could it not be referring to David or Solomon, Isaiah or Ezekiel, Elijah or Elisha? Were they not prophets, and did they not come from the people to whom Moses was speaking?
There were many Israeli prophets, but this segment of Deuteronomy is not referring to any of them. As I stated in point number three, Peter tells us quite plainly in the Book of Acts, chapter 3, that the prophet referred to here is Jesus.
Jesus is the sole mediator between God and Men (1 Timothy 2:5), and since He is Himself both God and Man (Philippians 2:6-7; John 1), He is the perfect One for the job. I bring this up because the context of the passage in Deuteronomy fits in nicely with this identification of Christ as mediator but suffers somewhat if any other individual (David, Isaiah, Muhammad) is the intended fulfillment of this prophecy.
Notice in verses 16-17 of Deuteronomy 18, Moses explains why God is going to raise up this coming prophet: "This is according to all that you asked of the LORD your God in Horeb on the day of the assembly, saying, 'Let me not hear again the voice of the LORD my God, let me not see this great fire anymore, or I will die.' The LORD said to me, 'They have spoken well'".
As a result of the Israelites not wanting to interact directly with the Father in His awesome power and perfect justice, and the Father accepting this idea as good, the idea of a mediator is proposed by Him. The Father acknowledged that a mediator was a good concept. Of course, the idea of Christ the Mediator had been God's plan all along (1 Peter 1:20; Revelation 13:8).
As Moses acted temporarily as a type of mediator (Exodus 32:11-14), and even then without fully experiencing the God he spoke with (Exodus 33:20-23), Jesus is the permanent and everlasting mediator (Hebrews 12:24), who's very words are the Words of God (John 1:1, 5:19), who sits at the right hand of the Father (Acts 2:33), who continues to intercede for us today (Hebrews 7:25). Thus Christ, and only Christ, perfectly fits the description of this singular prophet described in the book of Deuteronomy.
If we would like to claim that Muhammad was written about in the Christian Bible, then we need to point to the scriptures that could perhaps actually be referring to him. For example:
But even if we, or an angel from heaven, should preach to you a gospel contrary to what we have preached to you, he is to be accursed!
...or this one:
2 John 1:7
For many deceivers have gone out into the world who do not confess Jesus Christ as coming in the flesh. This is a deceiver and an antichrist.
...or here, in the words of Christ Himself:
"Beware of false prophets, who come to you in sheep's clothing, but inwardly they are ravenous wolves. You will know them by their fruits. Do men gather grapes from thornbushes or figs from thistles? Even so, every good tree bears good fruit, but a bad tree bears bad fruit. A good tree cannot bear bad fruit, nor can a bad tree bear good fruit. Every tree that does not bear good fruit is cut down and thrown into the fire. Therefore by their fruits you will know them."
If we must say the Bible prophesies of the coming of Muhammad, let us at least point to verses that fit the facts.
I find it very odd that a Muslim (as I take it the questioner is) would do all he can to prove his worldview is clearly revealed in the Christian scriptures that clearly teach not only Christ crucified (Psalm 22:16; Isaiah 53:8-10; Zechariah 12:10; Matthew 27:35, 28:5; Mark 15:25; John 19:18 Acts 2:36; 1 Corinthians 1:23, 2:2) and risen from the dead (Matthew 28:6; Mark 16:6; Luke 24:34; John 2:19-20, 20:9; Acts 4:10, 13:30; 1 Corinthians 15:20), but God the Son in human flesh (John 1:1-14; Philippians 2:6-7; Hebrews 1:1 - 2:15)! These teachings are anathema to Islam. Why attempt to claim that sources you find to be blasphemous actually teach "the truth"? Surely if I agree with you that the Bible prophesies of Muhammad and is therefore the Word of God, you can agree with me that what it teaches is actually true, namely, that Jesus died on the cross, rose from the dead, and is in fact God the Son!
With regards to 1 John 4:1, I am not sure what you are referring to. Here is the text:
"Beloved, do not believe every spirit, but test the spirits to see whether they are from God, because many false prophets have gone out into the world."
I don't see anything there about Muhammad praising Jesus without knowledge of Him. However, I would not claim that this text does NOT speak of Muhammad, for it seems to me that it does, since he is one of the many false prophets that have gone into the world.
Finally, I will be happy to review "The Choice" by Ahmed Deedat in the near future. Thank you for recommending it, even though I had to leave your recommendation out of the compiled question due to space limitations, I have mentioned it here to ensure you that it was noted.
Thanks for your questions and God bless you as you pursue the Truth (John 14:6).