To sacrifice is to give up something valuable or precious, often with the intent of accomplishing a greater purpose or goal. Sacrifice has always been a part of the gospel of Jesus Christ. It is a reminder of the great atoning sacrifice of Jesus Christ for all who have lived or will live on earth. Before the ministry of Christ, animal sacrifices were offered for this purpose .In ancient days, sacrifice meant to make something or someone holy. It has now come to mean to give up or suffer the loss of worldly things for the Lord and His kingdom so  after the Atonement of Christ, followers of Jesus Christ—by His direction—began to offer instead a “broken heart and contrite spirit”, a willingness to repent of sins and a desire to follow Jesus Christ and align one’s life with His commandments.     Source: http://www.lds.org