From Tad R. Callister’s book ‘The Infinite Atonement’:
The Atonement saves us all in the sense that we are all resurrected and return to God’s presence for judgment purposes without any effort on our part. It cannot, however, exalt us, unless we repent. If a person does not achieve exaltation, the issue is not the infinite nature of the Atonement; the issue is the repentant spirit of the individual. He can have exaltation if he will but repent. Each of us has the key that unlocks the cleansing powers of the Atonement, but we must turn it.
. . . .”Mercy cometh because of the atonement . . . and also mercy claimeth all which is her own; and thus none but the truly penitent are saved” (Alma 42:23-24).
Recognizing the Savior’s merciful outpouring, Truman Madsen spoke these consoling words: “Men have stood at pulpits and elsewhere—great men—and have testified that their knees have never buckled, that as one said of another, ‘He had nothing to hide.’ We have had monumental men who did not need redemption as much as they needed power, and who never fell very far from the communing light of which I have spoken. I cannot bear that kind of testimony. But if there are some of you who have been tricked into the conviction that you have gone too far, that you have been weighed down with doubts on which you alone have a monopoly, that you have had the poison of sin which it is impossible ever again to be what you could have been—than hear me.
“I bear testimony that you cannot sink farther than the light and sweeping intelligence of Jesus Christ can reach. I bear testimony that as long as there is one spark of will to repent and to reach, he is there. He did not just descend to your condition; he descended below it, ‘that he might be in all and through all things, the light of truth’ (Doctrine and Covenants 88:6.)” 7
The Atonement of the Savior covers every repentable sin known to man.8 This is both logical and reassuring. Certainly in the premortal council the Lord must have known the depths to which man would sink. He was no novice at creating. He had been over the course time and time again. He had observed our spirits throughout the eons. He understood the workings of each man’s heart. And he told the prophet Samuel, “The Lord seeth not as man seeth; for man looketh on the outward appearance, but the Lord looketh on the heart” (1 Samuel 16:7). He has witnessed the tragic war in heaven and seen one-third of his spirit brothers and sisters turn against him to choose the most notorious infidel of all time. Surely he understood there would be Sodoms and Gomorrahs and crimes of heinous proportions. And surely he took this into account as he worked with the Father in planning a redemption that would encompass it all.
. . . . if there are some of you who have been tricked into the conviction that you have gone too far, that you have been weighed down with doubts on which you alone have a monopoly, that you have had the poison of sin which makes it impossible ever again to be what you could have been—than hear me.
“I bear testimony that you cannot sink farther than the light and sweeping intelligence of Jesus Christ can reach. I bear testimony that as long as there is one spark of will to repent and to reach, he is there. He did not just descend to your condition; he descended below it, ‘that he might be in all and through all things, the light of truth’ (Doctrine and Covenants 88:6).” (197-199)
8. As discussed earlier (in the book) , there is no repentance for the ‘unpardonable sin’.