Alma 38:6 - 38:10
Alma 38: 6 Now, my son, I would not that ye should think that I know these things of myself, but it is the Spirit of God which is in me which maketh these things known unto me; for if I had not been born of God I should not have known these things.
Alma’s testimony is not an intellectual conversion. It was not the result of analyzing facts and coming to a conclusion that the gospel was true. It was revealed to him that the gospel was true. The Spirit of the Lord revealed its truthfulness to him. And if he had not undergone a deep personal crises and felt the need to know of the truthfulness of the words of his father, it would not have been revealed to him.
Alma 38: 7 But behold, the Lord in his great mercy sent his angel to declare unto me that I must stop the work of destruction among his people; yea, and I have seen an angel face to face, and he spake with me, and his voice was as thunder, and it shook the whole earth.
But in spite of Alma Jr’s bad behavior, the Lord sent an angel to him to shake him up a bit. The angel told him to stop trying to destroy the church and it scared the hell out of him. When the angel spoke, the earth shook and his voice was as if it were thunder.
Alma 38: 8 And it came to pass that I was three days and three nights in the most bitter pain and anguish of soul; and never, until I did cry out unto the Lord Jesus Christ for mercy, did I receive a remission of my sins. But behold, I did cry unto him and I did find peace to my soul.
The experience put him into a coma and for three days and nights, he experienced the extreme anguish of a guilty conscious. It might have continued, but when he cried out for Jesus, he felt an immediate suasion of a guilty conscious and a feeling that he had been completely forgiven. Now felt the peace of soul.
Alma 38: 9 And now, my son, I have told you this that ye may learn wisdom, that ye may learn of me that there is no other way or means whereby man can be saved, only in and through Christ. Behold, he is the life and the light of the world. Behold, he is the word of truth and righteousness.
Alma relates this experience to Shiblon so that he will realize how to gain and keep the feeling of a clear conscious. He is reiterating that having a testimony of Jesus Christ and acting on it is the only way that a person can have real peace in their life. No other philosophy or set of rules of behavior will produce the feelings of love and goodwill that the gospel can bring.
One might think after 6000 years or so of trying all sorts of systems of behavior in order to enjoy life and all of them failing, people might want to give the gospel of Jesus Christ a try.
Alma 38: 10 And now, as ye have begun to teach the word even so I would that ye should continue to teach; and I would that ye would be diligent and temperate in all things.
So Alma’s admonition to Shiblon is to continue in his faithfulness to his duty as a church representative and continue in his priestly duties. He just needs to be diligent and watch his appetites.