God's delight in obedience is good news because it means He is praiseworthy and reliable. If He did not delight in obedience, He would be a living contradiction: loving His glory above all things and yet not pleased by the acts that make His glory known. He would be two-faced and double-tongued. His beauty would vanish and with it all our delight! And He would be unreliable because you can't trust a God whose values are so fickle that He exalts Himself one minute and approves of insults the next.