Korihor argues with Alma in Alma 30 about the existence of a God. This kind of dispute wasn’t common when the Book of Mormon was translated and published in 1830, but is increasingly relevant today.
Korihor says that religions use the principles they teach to “usurp power and authority”, and “keep them in ignorance”. I think Korihor’s points actually may hold some water when held up to various religious practices like during apostate periods or where true faith has devolved into priestcraft. However, when held up to Alma’s beliefs, and by extension to the teachings of the Church of Jesus Christ, they hold no water. Because all members are not only encouraged, but almost required by virtue of the baptismal interview questions to first come to a testimony of these things themselves, those principles encourage individuals to gain a connection with God and discover if He is indeed real.
Korihor claims there is no evidence for God, Alma refutes this beautifully when he says:
A cynic could turn this verse and claim that existence isn’t direct proof of God, but I think Alma’s point is that Korihor can’t prove the non-existence of God either, and the non-existence of God with so many wonders seems even less plausible.
I like that Alma has learned to ask questions and seek truth himself, leading him not to be shaken when Korihor raises all sorts of disputes. The best way to progress is seek truth where it can be found and refute falsehoods when better information can be uncovered.