Commands

"All Your commands are righteous"  (Psalm 119:172)
God's commands aren't just a bunch of rules.  They tell us of His character.  We can actually get to know God better by learning and obeying His commands. I think this is why King David got so excited about God's law; he loved God and knew that the commandments were a reflection of who the Lord is.
Since God's people have received His Spirit, we have the power to live according to His commands.  As we depend on the Spirit rather than trying to make ourselves righteous by fleshly efforts, we find that God's commandments aren't at all burdensome.  This goes against human thinking, but it's true, and as I've begun to believe truth, it has brought me joy.