In Haggai 2:12–19, God drives home a very telling point to the prophet. If we place an unclean thing together with a clean one, the cleanness of the latter will not rub off onto the former. If I rub my dirty and ink-stained hands on a clean towel, the cleanness of the towel will not rub off onto my hands: rather it is dirt that is transferred, and the towel becomes dirty.
By this means the Lord made clear to Haggai and Judah that sin is contagious, but righteousness is not. We are not Christians simply because we belong to a good church, a good family, or a fine community. Moreover, a good profession of faith does not make us holy or godly.
Sin and injustice are all around us, and they readily rub off on us if we are not careful. To stand against this requires faith: it means that, being regenerate, we are governed by the power of God, not by the pressures of the group. We go against the current rather than with it, because the currents of our time are replete with injustice and ungodliness. We do not allow our speech to be governed by tale-bearing and nonsense but by grace and consideration.
In our day, we have exalted the feelings of the group to the place of God. “Group dynamics” has replaced morality, and all too many people respond to peer pressure rather than the law-word of God. For such people, the law is what people think and not what God says. Some churches try to capitalize on “group dynamics” by using the music, fads, and currents of the world as a means of attracting youth. They forget that faith involves a break with this fallen world, not a merger with it. Faith comes by the power of God, not by merging with the spirit of the age.
(From a Word in Season, Vol. 7)