Jacob 7:11 - 7:15

Jacob 7:11 And I said unto him: Then ye do not understand them; for they truly testify of Christ. Behold, I say unto you that none of the prophets have written, nor prophesied, save they have spoken concerning this Christ.

Jacob say that if he does believe the scripture, he does not understand what the center message of the scriptures is. They all testify of Christ. In fact there is not one prophet who does not talk about him in their preachings or writings.
[This is a concept that is hard for many to understand. Some think that Christianity is a new concept that come into being through Jesus Christ. To think that a person in Old Testament times was a Christian is unthinkable, particularly to a Jew. That there were Christians before Jesus Christ was born is a new concept to much of the so called Christian world, but central to the Latter-day Saints.]

Jacob 7:12 And this is not all—it has been made manifest unto me, for I have heard and seen; and it also has been made manifest unto me by the power of the Holy Ghost; wherefore, I know if there should be no atonement made all mankind must be lost.

Jacob now adds to this knowledge that he has both seen and heard by the power of the Holy Ghost that if a Messiah did not come and provide an atonement, we would not be able to have a path to protection or the ability to return to our heavenly home to live with our Father in Heaven ever again.

Jacob 7:13 And it came to pass that he said unto me: Show me a sign by this power of the Holy Ghost, in the which ye know so much.

Sherem sees that he cannot shake Jacob so he uses the “show me a sign” routine.
[Good indication of his truth character of being a very wicked man and an adulterer as well.]

Jacob 7:14 And I said unto him: What am I that I should tempt God to show unto thee a sign in the thing which thou knowest to be true? Yet thou wilt deny it, because thou art of the devil. Nevertheless, not my will be done; but if God shall smite thee, let that be a sign unto thee that he has power, both in heaven and in earth; and also, that Christ shall come. And thy will, O Lord, be done, and not mine.

Jacob does not want to go this route because Jacob knows that Sherem really does know that there is a need for a Messiah. Since Sherem is now under the inspiration of the devil it would be a waste of time to give him a sign since he is really under the direction of satan. So Jacob leaves that up to God to determine if Sherem should have a sign.

Jacob 7:15 And it came to pass that when I, Jacob, had spoken these words, the power of the Lord came upon him, insomuch that he fell to the earth. And it came to pass that he was nourished for the space of many days.

The Lord does now strike down Sherem with a sign and he is paralyzed to the point that he needs to be fed to be kept alive.