Alma 1:21 - 1:25

Alma 1:21 Now there was a strict law among the people of the church, that there should not any man, belonging to the church, arise and persecute those that did not belong to the church, and that there should be no persecution among themselves.

In relation to the harassment of the church members by non-believers, there were laws on the books making it illegal to do so.

Alma 1:22 Nevertheless, there were many among them who began to be proud, and began to contend warmly with their adversaries, even unto blows; yea, they would smite one another with their fists.

These laws did not seem to stop some people. Because some thought that because their doctrines were superior, that they began to contend with church members. But the church members were arguing back in turn and some of these confrontations even came to fist fights.

Alma 1:23 Now this was in the second year of the reign of Alma, and it was a cause of much affliction to the church; yea, it was the cause of much trial with the church.

As the situation between church members and the non-believers intensified, the church was in trouble. The confrontations and disputes were increasing in number and many in the church were now questioning the doctrines of the church.

Alma 1:24 For the hearts of many were hardened, and their names were blotted out, that they were remembered no more among the people of God. And also many withdrew themselves from among them.

This resulted in the excommunication of some church members and other just quitting the church all together.

Alma 1:25 Now this was a great trial to those that did stand fast in the faith; nevertheless, they were steadfast and immovable in keeping the commandments of God, and they bore with patience the persecution which was heaped upon them.

However, the faithful ones in the church were loyal to the church and withstood the harassment of the non-believers and those who had quit the church to join the new churches that had sprung up around them. They took the persecution knowing that in time they were be delivered.
[One might wonder if we will also had to endure the same in our day. I think yes. We can see that to some extent in the media and with other churches calling us "non-christian."]