There are both unconditional and conditional benefits of the atonement of Jesus Christ. All persons who take a physical body through birth will be raised from the grave in immortality through resurrection; this blessing is unconditional and comes freely through Christ.
Eternal life, however, comes only to those who believe and obey (see D&C 29:43). This doctrine, enunciated with unmatched clarity by Abinadi and repetitiously attested by Book of Mormon prophets, has been a matter of considerable confusion in the Christian world.
Though it is true that our Savior suffered the pains of all men, that he agonized in Gethsemane and on Calvary for the iniquities of “every living creature ... who belong to the family of Adam” (2 Nephi 9:21; cf. D&C 18:11; D&C 19:16), that suffering nevertheless becomes efficacious in its fulness only in behalf of those who repent and come unto him.
The Lord made possible, through his atoning sacrifice-an infinite act of love and mercy-the exaltation of all, but such becomes available to the individual only “on conditions of repentance” (Alma 42:13; D&C 18:12; D&C 19:16-17). See also verses 26-27; Mosiah 16:5.