Sin is uncomfortable, or at least it should be. For those who strive to be holy (cf. 1 Pet. 1:16), even the smallest blemish should be bothersome to the point of compelling us to address it. Unfortunately, that is not always the case, especially when the sin involves other members of the congregation. For a number of reasons we try to marginalize or ignore the problem, hoping it will work itself out. But, like ignoring early symptoms of a major health problem, we do so to our own demise. Like Pergamos and Thyatira (Rev. 2:14-15; 20), dying congregations tolerate sin.
Amos 5:15 commands “hate the evil and love the good.” Paul said genuine love abhors what is evil and clings to what is good (Rom. 12:9). These two actions are not mutually exclusive and yet so often we live as though they are. The churches in Pergamos and Thyatira knew what it was to cling to the good but failed in hating the evil. Pergamos tolerated the doctrines of Baalam and the Nicolaitans while Thyatira allowed a Jezebel to seduce brethren to commit fornication.
Sin, in every form, will spread through a congregation like a poison and kill the church if allowed to go on unchecked. Joshua learned that lesson regarding Achan and the church at Corinth was rebuked sternly for turning a blind eye to sexual immorality in the congregation (Josh. 7; 1 Cor. 5). Though it may not be easy, we have an obligation to deal with sin in the church. Though a body may appear healthy externally, it may be rotting away and dying internally. Such is the reality of a congregation that allows sin to fester in its midst.