I love Alma the Younger's account of his conversion. We remember the story told earlier in the Book of Mormon, where it talks about what happened to Alma the Younger and the Sons of Mosiah. They went about seeking to destroy the church. After doing this for some time, they were hanging out together and were visited by an angel. After hearing the angel speak to them, Alma ended up basically collapsing as if he were dead. He couldn't move, speak, or interact. He was like this for 3 days. During this time, he went through a conversion process.
After this, Alma and the Sons of Mosiah were changed men. They left to preach the gospel and had great success. Many people were brought to the knowledge of the gospel and were converted because of their teachings.
Eventually, Alma sits down to teach his sons, one at a time. He sits down with Helaman and shares what happened to him while he was unable to move or speak.
"16 And now, for three days and for three nights was I racked, even with the pains of a damned soul.
17 And it came to pass that as I was thus racked with torment, while I was harrowed up by the memory of my many sins, behold, I remembered also to have heard my father prophesy unto the people concerning the coming of one Jesus Christ, a Son of God, to atone for the sins of the world.
18 Now, as my mind caught hold upon this thought, I cried within my heart: O Jesus, thou Son of God, have mercy on me, who am in the gall of bitterness, and am encircled about by the everlasting chains of death.
19 And now, behold, when I thought this, I could remember my pains no more; yea, I was harrowed up by the memory of my sins no more.
20 And oh, what joy, and what marvelous light I did behold; yea, my soul was filled with joy as exceeding as was my pain!" (Alma 36:16-20)
I love this account because I think this is basically the personal experience of anyone who has gone through the repentance process. Obviously the timeline can be a lot different for different people, but the experience is the same. First, there is the guilt and sorrow for having done something you understand is wrong. This is the torment that Alma describes. He suddenly has a very clear understanding that what he was doing was wrong, but he didn't know what to do about it. All he could do for 3 days was to think about what he'd been doing wrong.
I love the phrase "as my mind caught hold upon this thought". I think even for more minor things, we feel guilt for what we've done, but there comes a point that we really realize that Christ made an atonement for all of us, and that we really can be forgiven. In that moment, the hope and joy that I have felt, which comes at least in part from the Spirit, testifying of Christ, and the reality of the Atonement that allows us to repent.
Alma describes that he was racked with eternal torment and that he remembered all his sins and iniquities. He felt like he'd rather be "banished and become extinct, both soul and body" than to face God at the judgement day. Once he remembered the Savior the atonement, and "caught hold upon this thought", his experience was that there could be "nothing so exquisite and sweet as was [his] joy". I think it made it all the more sweet because of the bitterness that he was experiencing before, and how polar opposite those feelings were.
While I can't say I know what it feels like to realize that I caused the spiritual demise for some people, I have definitely sinned, and have felt that torment that comes with knowing you have sinned. I have also felt the opposite, the joy of realizing that Jesus Christ is my savior, not just in title, but in action.
I know the atonement is real. I know that Christ did that for me and for all of us, and I know that even though I'm not perfect, I can repent and still be able to return to our Heavenly Father in the end. How wonderful is that thought, truly causing, as Alma describes, joy that is more exquisite and sweet than anything.