We are our own worst enemy. How often we are deterred by our own spiritual weakness from calling on God in prayer. We have a thousand really good reasons why should not pray. We imagine that God could not possiblylisten to the prayers of a sinner such me. We think that we need to get our "life turned around" so that we can pray with a proper intent. We imagine that if we don't pray in some specifically prescribed way the Lord will be unable to understand and act on our petitions. We are deluded to think that unless our heart is pure the Lord would not entertain our requests and see to our need. If only those who have pure hearts should pray, no one would ever be ready to pray. And if we really had pure hearts, there would be no reason to pray. Trouble would never befall us, we would never sin, and we would certainly not need God to send His Son into the world to carry the world's sins away (Jn 1:29). We would have no need ever to cry, "Have mercy on me, O God" (Ps 51:1).

True Christian blessedness consists not in your purity, but in the purity of God's Son, who offered Himself  as "the propitiation for our sins, and not for ours only but also for the sins of the whole world" (1Jn 2:2). True Christian life includes the truthful confession of our sin and weakness. This is completely counter to the world's usual pattern of thought. The world thinks that Christianity is about your making yourself better, pulling yourself up by your own bootstraps, even if with God's help. Whereas faithful Christianity is the admission of inability, so that God can become all things in all. He is the propitiation for our sins. We are not the propitiation for our own sins. That means we are and remain sinners. God in Christ has taken care of our sin and weakness in His Son. The result of this is that we can admit our sin, even accept it. By accept it, I don't mean to concur with sin or revel in it, but accept the accusation of the law that we are mired in sin and depravity. Only then will be cry out, "Have mercy on me, O God!"

The world thinks that such a thing can only be said by us and accepted by God when we "bring something to the table." The world thinks that we must show God by our disposition and works that we are really in the game with Him. We must display our good will and then He will hear us. Such thinking is a subtle (or not so subtle) kind of work righteousness. It presumes that we must meet preconditions before God will graciously condescend to hear us. This is a grace that is paid for by us, and therefore not grace at all, but an earned credit. If we had to meet preconditions for our Father to hear our prayer, He would not have much listening to do. Even earthly fathers do not hear the requests of their children because they are worthy to ask, but merely because they are dear children.

Martin Luther