When the law is proclaimed as simply a moral precept for you to look at and try to do, then we often wind up looking inward rather than at the completed work of Christ on our behalf. It’s important to understand why Christ fulfilled the law. Because as He made clear, it has to be fulfilled perfectly (Mt 5:48) . James says that if you fail at any little point, you’re guilty of breaking it all. (Ja 2:10). The law is like a mirror, it shows us where we fall short, but there’s no power in it to clean ourselves up. When churches that are preaching these sermons focused on you just trying a little harder they wind up having to continually lower the standards of the law.
When a Christian under this starts to look at himself and the law, and sees that he is not doing it, he he can start to wonder if he’s really a Christian at all. So, he gets’ depressed. The whole church can start feeling these doubts and fears and they need some comfort. So, these pastors start delivering these therapeutic sermons, and lowering the law down to help these people not feel so rotten. This is often what happens under moralistic preaching. Either that or self deception, and pride set in.
The problem is not that the law needs to be relativized and lowered. It needs to be preached as absolute law, with perfection as the standard. Then we need to hear that so it kills us and our efforts to make ourselves clean by following the law. Then our only hope is to look to our perfect law keeper. We need to rest on the righteousness of Christ, merited on our behalf. That’s what gives us power against sin, and the proper motive to seek to love neighbor knowing that the law’s perfection has been kept for us.
Only that proper law/gospel distinction will keep us from this moralistic, therapeutic deism that most American churches are caught up in. That law that crushes us and all of our attempts to perfect ourselves and forces us out of this self-focused self-justification mindset to rest in the Christ-focused gospel of Christ’s perfection on our behalf.