Jesus Christ is the great Redeemer of mankind because he, through his atonement, paid the price for the sins of mankind and made possible the resurrection of all people.

I know that my redeemer liveth, Job 19: 25. I will help thee, saith thy redeemer, the Holy One of Israel, Isa. 41: 14 (Isa. 43: 14; 48: 17; 54: 5; 59: 20). I the Lord am thy Savior and thy Redeemer, Isa. 49: 26 (Isa. 60: 16). Call his name Jesus: for he shall save his people from their sins, Matt. 1: 21. The Son of man came to give his life as a ransom for many, Matt. 20: 28 (1 Tim. 2: 5-6). The Lord God of Israel hath visited and redeemed his people, Luke 1: 68. We were reconciled to God by the death of his Son, Rom. 5: 10. Jesus Christ gave himself for us, that he might redeem us from all iniquity, Titus 2: 13-14. Jesus Christ washed us from our sins in his own blood, Rev. 1: 5. Redemption cometh in and through the Holy Messiah, 2 Ne. 2: 6-7, 26. The Son took upon himself men's iniquity and transgressions, redeemed them, and satisfied the demands of justice, Mosiah 15: 6-9, 18-27. Christ came to redeem all those who would be baptized unto repentance, Alma 9: 26-27. He shall come into the world to redeem his people, Alma 11: 40-41. Redemption comes through repentance, Alma 42: 13-26. Jesus Christ came to redeem the world, Hel. 5: 9-12. Christ redeemed mankind from physical and spiritual death, Hel. 14: 12-17. Redemption cometh by Christ, 3 Ne. 9: 17. I am he who was prepared from the foundation of the world to redeem my people, Ether 3: 14. The Lord your Redeemer suffered death in the flesh, D&C 18: 11. Christ suffered for all if they repent, D&C 19: 1, 16-20. Little children are redeemed through the Only Begotten, D&C 29: 46. I have sent mine Only Begotten Son into the world for the redemption of the world, D&C 49: 5. Christ is the light and Redeemer of the world, D&C 93: 8-9. Joseph F. Smith received a vision of the redemption of the dead, D&C 138. We believe that through the atonement of Christ, all mankind may be saved, A of F 1: 3.