This is an interesting verse because it shows the effect of the members on the unbelievers. One might think that the actions of church members would have had no effect on the general population, but their bad example set the lead in matters of spirituality. Unfortunately, things haven’t changed much since the days of Alma. Members of the church today, on occasion, set a bad example for potential investigators. They often underestimate how far the ripples travel when they jump in the pond of sin. How many times have you heard someone say, “the church is perfect, but the members aren’t”? Or, “you can’t judge the church by its members”? These sorts of statements try to keep investigators from judging the church based on the actions of its members. Obviously this argument is important only when the members of the church are setting a bad example.
But how else can an investigator determine the benefits of membership? To tell an investigator that the church should not be judged by the actions of its members is just not doctrinally correct. The Savior has said, by their fruits ye shall know them (Matt 7:20), and By this shall all men know that ye are my disciples, if ye have love, one to another (Jn 13:35), and Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven (Matt 5:16). The members of the church should be living lives which are so in tune with the Spirit and the commandments that we could say to investigators, “you can judge the church by the actions of its members. We are confident that you won’t find anything in their behavior which is at odds with the will of God.”
George F. Richards
“We are judged, as a people, largely, by the conduct of the adherents to this faith, and the doctrines of the gospel; so that no man claiming a standing in the Church is at liberty to disregard the commandments of the Lord, to be a drunkard, or to be immoral, or otherwise set a bad example. The lives of those who profess to be Saints should conform strictly to the precepts of the gospel, should be in complete harmony therewith. When people see those whose lives are not in harmony and not commendable, I would have them know, whether they be in the Church or out, that it is due to the weaknesses and fallibilities of mortal men and women, and no action or conduct of any individual, however high he may be in authority, can affect the infallibility of the Gospel, change the truth, or make the truth a falsehood, or render any ordinance of the gospel unnecessary. People ought not to reach wrong conclusions in judging the work of the Lord, and the people of the Lord, because of the unrighteous conduct of some individuals. It may be asked, why do you retain them as members of the Church? The only answer I have to make is this: Our mission is to save and not to destroy; and while they are members of the Church, we will labor for their reformation with a hope of bringing them, sometime, to repentance, and faithfulness in serving the Lord. That is our mission.” (Conference Report, Apr. 1911, p. 43)
Ezra Taft Benson
"One of our best missionary tools is the sterling examples of members who live the gospel. This is what the Lord meant when he said to the Church, ’Zion must increase in beauty, and in holiness….Zion must put on her beautiful garments’ (DC 82:14). (Ensign, May 1985, p. 7 as taken from Latter-day Commentary on the Book of Mormon compiled by K. Douglas Bassett, p. 252)
Spencer W. Kimball
“…how much easier it is to understand and accept if the seeker after truth can also see the principles of the gospel at work in the lives of other believers. No greater service can be given to the missionary calling of this Church than to be exemplary in positive Christian virtues in our lives.” (Teachings of Spencer W. Kimball, p. 555 as taken from Latter-day Commentary on the Book of Mormon compiled by K. Douglas Bassett, p. 252)