It was hard not to post this entire passage because there are so many great principles taught in this chapter. But these particular verses really explain the purpose of the law of Moses which included blood sacrifice, and what is expected of us today with regard to the atonement of Jesus Christ.
Alma 34: 13-17
13Therefore, it is expedient that there should be a great and last sacrifice, and then shall there be, or it is expedient there should be, a stop to the shedding of blood; then shall the law of Moses be fulfilled; yea, it shall be all fulfilled, every jot and tittle, and none shall have passed away.
15And thus he shall bring salvation to all those who shall believe on his name; this being the intent of this last sacrifice, to bring about the bowels of mercy, which overpowereth justice, and bringeth about means unto men that they may have faith unto repentance.
16And thus mercy can satisfy the demands of justice, and encircles them in the arms of safety, while he that exercises no faith unto repentance is exposed to the whole law of the demands of justice; therefore only unto him that has faith unto repentance is brought about the great and eternal plan of redemption.
17Therefore may God grant unto you, my brethren, that ye may begin to exercise your faith unto repentance, that ye begin to callupon his holy name, that he would have mercy upon you;