Jacob 4

Jacob understood that the natural man of all nations, much like -

"...the Jews were a stiffnecked people; and they despised the words of plainness, and killed the prophets, and sought for things that they could not understand. Wherefore, because of their blindness, which blindness came by looking beyond the mark, they must needs fall; for God hath taken away his plainness from them, and delivered unto them many things which they cannot understand, because they desired it. And because they desired it God hath done it, that they may stumble." (Book of Mormon | Jacob 4:14)

The natural man does not want to hear that which is plain and clear. They only want to justify themselves. The "mark" is Jesus Christ and His teachings. It is His true servants, the prophets and priesthood leaders, that teach the things of truth and plainess for -

"...he that prophesieth, let him prophesy [teach] to the understanding of men; for the Spirit speaketh the truth and lieth not. Wherefore, it speaketh of things as they really are, and of things as they really will be; wherefore, these things are manifested unto us plainly, for the salvation of our souls." (Book of Mormon | Jacob 4:13)

In all sincerity, Jacob writes of his motives that -

"...whatsoever things we write upon anything save it be upon plates must perish and vanish away; but we can write a few words upon plates, which will give our children, and also our beloved brethren, a small degree of knowledge concerning us, or concerning their fathers—
3 Now in this thing we do rejoice; and we labor diligently to engraven these words upon plates, hoping that our beloved brethren and our children will receive them with thankful hearts, and look upon them that they may learn with joy and not with sorrow, neither with contempt, concerning their first parents.
4 For, for this intent have we written these things, that they may know that we knew of Christ, and we had a hope of his glory many hundred years before his coming; and not only we ourselves had a hope of his glory, but also all the holy prophets which were before us." (Book of Mormon | Jacob 4:2 - 4)

Therefore -

"...marvel not that I tell you these things; for why not speak of the atonement of Christ, and attain to a perfect knowledge of him, as to attain to the knowledge of a resurrection and the world to come?" (Book of Mormon | Jacob 4:12)

Wherefore -

"...seek not to counsel the Lord, but to take counsel from his hand..." (Book of Mormon | Jacob 4:10)