This last appeal [i.e., Psalm 6:5] may be the most powerful of all because God is passionate for His own fame and glory. As a holy God, He perfectly and infinitely loves everything good, beautiful, and true, and He perfectly hates everything false and wicked (Psalm 5:4-6). God Himself is the most infinitely good, true, and beautiful thing in the universe. There is nothing more glorious, great, and grand than Him. So it follows that God must love Himself above all else if He is to be true to His character as a holy God. If God loved anything else more than He loved Himself, even for a moment, He would commit idolatry and be guilty of sin—unthinkable! Since God rightly loves Himself more than anything else, He is passionate for His glory.
What’s more, as men and women we should perfectly love everything good, beautiful, and true, too. If you think about it, we find our greatest joy in appreciating good and beautiful things: the smile on a six-year-old’s face, the turning leaves, a perfect dovetail joint. When we see goodness, beauty, and truth, it fills our hearts. God is the most good, beautiful, and true being in the universe! When we see Him in His glory, the sight of Him fills our hearts with joy.
— James Johnston, The Psalms (Vol. 1): Rejoice, The LORD is King, Kindle Location 1425ff.