Psalm 119:6 David had known shame, and here he rejoices in being freed from it through fixing his eyes on the Lord. Sin brings shame, and when sin is gone, the reason for being ashamed is gone as well. There are two applications for us:
1) Seek holiness, avoid sin, and pursue obeying the Lord’s commandments.
2) Seek repentance and put your hope in Christ when you do sin.
These are equally important in the Christian life. Brushing off the seriousness of our sin and casually assuming that since we’re Christians we have the freedom to do what we want is not a biblical concept. Christian liberty understood in this way ignores all the commands in scripture for us to pursue righteousness and holiness. Yes, we will fail at living perfectly this side of heaven, but using Christ’s atonement as a license to live however we want distorts the gospel.