Moroni 7

As Mormon taught the Plan of Salvation, he said -

"...God knowing all things, being from everlasting to everlasting, behold, he sent angels to minister unto the children of men, to make manifest concerning the coming of Christ; and in Christ there should come every good thing..." (Book of Mormon Moroni 7:22)

And -

"...God also declared unto prophets, by his own mouth, that Christ should come." (Book of Mormon Moroni 7:23)

And he didn't do this in just one way but -

"...there were divers ways that he did manifest things unto the children of men, which were good..." (Book of Mormon Moroni 7:24)

"Wherefore, by the ministering of angels, and by every word which proceeded forth out of the mouth of God, men began to exercise faith in Christ; and thus by faith, they did lay hold upon every good thing..." (Book of Mormon Moroni 7:25)

And then Mormon asks the members of his synagogue -

"...my beloved brethren, have miracles ceased? Behold I say unto you, Nay; neither have angels ceased to minister unto the children of men." (Book of Mormon Moroni 7:29)

And of the purpose of angels, Mormon teaches -

"...behold, they are subject unto him, to minister according to the word of his command, showing themselves unto them of strong faith and a firm mind in every form of godliness.
31 And the office of their ministry is to call men unto repentance, and to fulfil and to do the work of the covenants of the Father, which he hath made unto the children of men, to prepare the way among the children of men, by declaring the word of Christ unto the chosen vessels of the Lord..." (Book of Mormon Moroni 7:30 - 31)

Why to these chosen vessels?

"...that they may bear testimony of him.
32 And by so doing, the Lord God prepareth the way that the residue of men may have faith in Christ, that the Holy Ghost may have place in their hearts, according to the power thereof; and after this manner bringeth to pass the Father, the covenants which he hath made unto the children of men." (Book of Mormon Moroni 7:31 - 32)

For -

"...Christ hath said: If ye will have faith in me ye shall have power to do whatsoever thing is expedient in me." (Book of Mormon Moroni 7:33)

And then Mormon warns all generations -

"...my beloved brethren, if this be the case that these things are true which I have spoken unto you, and God will show unto you, with power and great glory at the last day, that they are true, and if they are true has the day of miracles ceased?
36 Or have angels ceased to appear unto the children of men? Or has he withheld the power of the Holy Ghost from them? Or will he, so long as time shall last, or the earth shall stand, or there shall be one man upon the face thereof to be saved?
37 Behold I say unto you, Nay; for it is by faith that miracles are wrought; and it is by faith that angels appear and minister unto men; wherefore, if these things have ceased wo be unto the children of men, for it is because of unbelief, and all is vain." (Book of Mormon Moroni 7:35 - 37)

"...wherefore, if these things have ceased, then has faith ceased also; and awful is the state of man, for they are as though there had been no redemption made." (Book of Mormon Moroni 7:38)

"...Wherefore, I beseech of you, brethren, that ye should search diligently in the light of Christ that ye may know good from evil; and if ye will lay hold upon every good thing, and condemn it not, ye certainly will be a child of Christ." (Book of Mormon Moroni 7:19)