25 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; and thus it was until the coming of Christ.
26 And after that he came men also were saved by faith in his name; and by faith, they become the sons of God. And as surely as Christ liveth he spake these words unto our fathers, saying: Whatsoever thing ye shall ask the Father in my name, which is good, in faith believing that ye shall receive, behold, it shall be done unto you.
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.
Source: Moroni 7:25-26,36-37; The Book of Mormon: Another Testament of Jesus Christ