Tolerance of sin is a dagger in the heart of any local church.  Paul was forced to remind the church at Corinth of this when they allowed a sexually immoral member to go undisciplined, seemingly, taking pride in their open-mindedness toward sin.  

1 Corinthians 5:6-7 (KJV)
⁶  Your glorying is not good. Know ye not that a little leaven leaveneth the whole lump? ⁷  Purge out therefore the old leaven, that ye may be a new lump, as ye are unleavened. For even Christ our Passover is sacrificed for us:

Sin can spread through a church like leaven (yeast) spreading through a lump of dough.  It must, therefore, be purged, or else it will destroy the church.  The church at Corinth would be ruined if they did not take disciplinary action against the fornicator.  Paul’s apostolic demand was to deliver him to Satan for the destruction of the flesh (1 Corinthians 5:5).

A model church does not tolerate sin.  Too many, otherwise sound, churches are unwilling to discipline members who are living in sin.  I am not sure what their reason is for not doing so.  Perhaps, they think they are showing love to the one in sin, but, in reality, their love is lacking.  It does not do the one in sin any good to tolerate his or her behavior, but, instead, encourages them to continue in the sin.  Paul exhorts us to have the proper kind of love.

Philippians 1:9 (ESV)
⁹  And it is my prayer that your love may abound more and more, with knowledge and all discernment,

If a church is a loving church, that is, a church that loves both God and man, it will keep the command to discipline those who continue in sin, keeping the church free from defilement.  What does this discipline entail?  Paul tells us.

1 Corinthians 5:11 (ESV)
¹¹  But now I am writing to you not to associate with anyone who bears the name of brother if he is guilty of sexual immorality or greed, or is an idolater, reviler, drunkard, or swindler—not even to eat with such a one.

2 Thessalonians 3:6 (ESV)
⁶  Now we command you, brothers, in the name of our Lord Jesus Christ, that you keep away from any brother who is walking in idleness and not in accord with the tradition that you received from us.

These passages make the action a church must take very clear—church discipline involves the withdrawal of all fellowship and association.  Who is to participate in this discipline?  The whole church.  Paul said that the initial action should take place “when you are assembled in the name of the Lord Jesus…” (1 Corinthians 5:4).

Sin will always be offensive to God, and it should be to us as well.  It is the only thing that can separate man from God (Isaiah 59:1-2; 1 John 1:5-6).  Since God will have no fellowship with those living in sin, we should not either.  As local churches, let us not ignore this important command.  We must discipline unfaithful members prayerfully and with the hope that they will repent and come back to the Lord, but we must do it if we wish to be model local churches.

As you wind down for the night, think about these things.