Ok, I admit it. I'm a theology geek. I have been recently meditating on Romans 6-8 and have found myself drawn to Luther's Heidelberg Disputation in my bedtime reading as a result. In my opinion this is one of his greatest works. In it he contrasts what he calls a theology of glory with a theology of the cross.
By theology of glory, Luther means adhering to the law. A theology of glory considers grace as a supplement to whatever I cannot accomplish by my own willpower. The problem with this is that the law and our efforts leave us unable to really change and deal with our brokenness. We take a low view of sin and its corrupting power, and too much stock in our own abilities. What is more, Luther views our good works as evil when they are done apart from God. Thesis 8 states, "by so much more are the works of man mortal sins when they are done without fear and in unadulterated, evil self-security." In addition, he states in thesis 16, "the person who believes that he can obtain grace by doing what is in him adds sin to sin so that he becomes doubly guilty."
The answer to this is the cross. "It is certain that man must utterly despair of his own ability before he is prepared to receive the grace of Christ" (thesis 18). We must know the God who has suffered. It is only through Christ's work that we are able to do any good work. Good works, done as law on our own, are addictive. Thus, the addict needs an intervention to change, and that intervention is the cross where God himself crucifies our desires, even the good ones when thought of apart from God. It is, then, not what we do but what we believe.
Sometimes we can shy away from delving into thinking on these things. Attending the next event or meeting is no substitute for reflection on the God who saves. But it is only through a robust theology of the cross that we will find true power and success in ministry. We will do well to think on these things.