There are 3 main characters of Alma 8-12:
- Alma (the younger)
If you rewind time to look at each of their lives as they’ve grown up, each had seasons of relative wickedness. Alma the younger shares his story several times, he actively fought against the church. Zeezrom was actively fighting against Alma and Amulek when they came to Ammonihah to preach. Amulek has a less clear back story but it says the following in Alma 10:
Even Amulek had hardened his heart at one point and rebelled against God. It’s notable that these are some of the key missionary examples in the Book of Mormon. The only missionary of perfect conduct was Jesus. It’s unrealistic to expect perfection from missionaries or any religious leader, and even they come from very different (often difficult) backgrouonds.