'For I am not ashamed of the gospel, for it is the power of God for salvation, to the Jew first, and also to the Greek.' Romans 1:16
Presumably we Christians believe that the gospel is powerful for salvation, for bringing men from darkness to light, from condemnation to justification, from enmity with God to reconciliation with him. In essence, for assuring that those who believe in Christ will go to heaven when they die.
Yet in some areas we act as if this is the only thing that the gospel is good for - holy fire insurance - and that it has no other effect before we die.
Certainly it is true that for the gospel to be powerful to change my behavior or my condition, it must first be powerful in bringing me from spiritual death to spiritual life - 'salvation' in its narrowest sense. But then, after powerfully changing my eternal condition, it is powerful for my transformation into the likeness of Christ - 'salvation' in its fullest sense.
When we say, however, that we can't discipline other members of our congregations, or exhort those contemplating divorce to consider other solutions, or challenge men to holiness, or expect better things from those calling themselves 'Christian,' we are saying that the gospel is not powerful. We are saying that though the gospel is powerful to save me from hell, it is impotent to make me a resident of heaven.
In fact, the church has forsaken the transformation power of the gospel in favor of worldly methods. We are saying, in effect, that the the truth cannot, in fact, set us free.