These verses provide a paradigm for how to teach the gospel according to the Holy Order of God, which is the Melchizedek Priesthood (D&C 84:18–19; 107:3). In part, we should use the testimonies of the apostles, prophets, and righteous souls who have gone before (D&C 52:9), bear our personal witness, and then teach others how we came to know the truth.
Suppose there were a giant sign that read: “Baptisms, Gifts of the Holy Ghost, Priesthood Ordinations, Temple Marriages—$10,000 each. Payment in Advance.” How hard would you work to earn each and all of these blessings? What would you give to know the Lord? How much do you really want to know him?
Alma asks, essentially, How do you suppose I know these things are true? How did I gain my testimony? It did not come solely from my dramatic experience with the angel!
Gospel knowledge and spiritual change require a lot of work. Like Alma, you have to fast and pray many days, and then the sure knowledge comes through the Holy Ghost. It is not a matter of a single day; it is a lifetime pursuit. Most converts to the Church receive their initial testimony not through angelic visitations or visions but through the sweet, gentle, yet powerful witness from the Holy Ghost; but there’s much spiritual work to be done after that.
Alma would have undoubtedly admitted at this point: I still have many questions, but I do not doubt. Doubt is spiritual poison.