Paul explains to the Galatians the distinction between grace and law and in doing so shows them why the Law was given in the first place, and how it prepares people for the Gospel and serves the goals of the Gospel.
The Spirit leads us to love and to know His law and to obey it. The law is the tool of liberty and victory to see His work and purposes established.
We live in a culture of self-righteousness and so we recoil at any hint that we need to be righteous. Political correctness itself is a kind of self-righteousness, smugly condemning those who believe in moral absolutes.
This Psalm of humility exalts the Law of God, and points us to Christ. The theme of the Psalm is the glory of God.
To judge others by human standards is both hypocritical and self-blinding. Whoever judges by the word of God begins his censure with himself.
We are commanded to respect the life and reputation of our enemy (don’t murder, don’t slander), respect his property (don’t steal, don’t covet), etc. Jesus instructs us to pray for and bless our enemy.
We live in a murderous culture where violence and suicide are leading causes of death.
Sin is deceitful, offering us many ways to make us happy, but ultimately all but Christ's offer of blessed life leads to misery and death.
We don't merely preface our plans with "if the Lord wills" but we want embedded in our character the knowledge that our lives are under God's control.