"We believe that through the Atonement of Christ, all mankind may be saved, by obedience to the laws and ordinances of the Gospel." Article of Faith 3
"Grace is the help or strength given through the Atonement of the Lord Jesus Christ. Through the grace of God, everyone who has lived will be resurrected. All spirits ever born on earth will be reunited with their bodies, never again to be separated. Through His grace, the Lord also enables those who live His gospel to repent and be forgiven.
Grace is a gift from Heavenly Father given through His Son, Jesus Christ. The word grace, as used in the scriptures, refers primarily to enabling power and spiritual healing offered through the mercy and love of Jesus Christ.
Everyone on earth experiences physical death. Through the grace of Jesus Christ, all will be resurrected and will live forever. They will be saved. "But now is Christ risen from the dead, and become the firstfruits of them that slept. For since by man came death, by man came also the resurrection of the dead. For as in Adam all die, even so in Christ shall all be made alive," 1 Corinthians 15:20-22 and 2 Nephi 9:6-13.
Because of personal choices, everyone also experiences the effects of sin, 1 John 1:8-10 and Mosiah 16:4. These effects are called spiritual death. No one can return to the presence of God without divine grace. Through the Atonement, we all can be forgiven of our sins and become clean before God. To receive this enabling power, we must obey the gospel of Jesus Christ, which includes having faith in Him, repenting of our sins, being baptized, receiving the gift of the Holy Ghost, and trying to follow the teachings of Jesus Christ for the rest of our lives, Ephesians 2:8-9, James 2:17-22, 2 Nephi 25:23, and 2 Nephi 31:20. 'This eternal life spoken of is eternal life in the presence of God. Without this we have eternal damnation in the presence of the devil. All are saved from the death of the body.' GC
The grace of God helps us every day. It strengthens us to do good works we could not do on our own. The Lord promised that if we humble ourselves before Him and have faith in Him, His grace will help us overcome all our personal weaknesses, Ether 12:27." Paraphrased from Topical Guide, LDS.org