1 Timothy 1:9, 10 We also know that the law is made not for the righteous but for lawbreakers and rebels, the ungodly and sinful, the unholy and irreligious, for those who kill their fathers or mothers, for murderers, for the sexually immoral, for those practising homosexuality, for slave traders and liars and perjurers - and for whatever else is contrary to the sound doctrine
Paul says that the law is not for righteous people. At first blush this may sound a little odd but Paul's point is that God's law shows you where you have gone wrong before God not how to get right with him. It is more like a proprietary plaque revealer than like a toothpaste. There are products that will stain the plaque on your teeth so that you can see it more clearly. You then have to set about the cleaning process. The law is a little like that product in that one of its main uses is to reveal the sin in your life. It is ideal for lawbreakers and rebels then, the ungodly and sinful, the unholy and irreligious as the first table would have in mind, and, as for the second table, those who kill their fathers or mothers, (number 5) for murderers, (number 6) for the sexually immoral, for those practising homosexuality, (number 7) for slave traders (number 8) and liars and perjurers (number 9) and indeed for whatever else is contrary to the sound doctrine, one of the great concerns of these letters (see 2 Timothy 4:3, Titus 1:9). The Law then can show us where we are going wrong, where we are unsound. That is the way to use it - not as a means of becoming righteous but in order to reveal sin in your life and in your heart. A faithful preacher will preach the law in such a way that he exposes to his hearers the fact of their sin.