This is an interesting statement in that most people would be quite understanding of the traditions of their fathers, and would rarely indicate that they were wicked. In this case, however, we will see some specific points on which this allegation of wickedness has been raised.
Textual: The referent for the speaker in this case is a little lost in the cast of characters. Verse 6 tells us that it is “the king.” Of course Lamoni is a king, and is mentioned. However, it is most likely that “the king” would refer to the over-king, or Anti-Nephi-Lehi.
“To Convince Us of the Traditions of Our Wicked Fathers”
This verse should be seen in contrast to the vehement hatred of the father of Lamoni that was manifest when he met Alma on the road (Alma 20:13). This is a people who had been steeped in a tradition of hatred and mistrust of all Nephites. The softening of the Spirit not only had to convert them to God, it had to accept that conversion at the hands of a people that they were raised to believe were liars.
This was an essential change in the entire picture of the world that these former Lamanites had held. Not only had their understanding of the physics of the world changed (for religion served that function for the ancients) but they also had their entire concept of political and social reality altered. These were a people who had undergone a wrenching transformation, and it is not surprising that one of the first things noted in this discourse is that great shift from seeing Nephites as the mortal enemy to seeing them as deliverer’s of the word of God.