Remember those cartoons where the baby bear rears up on its back legs and growls at an enemy, watching with glee as the enemy scampers away? The baby feels such pride, and then the camera zooms out to show the mama bear towering in the background, the real source of the enemy's fear.
That's how I feel when I read this Psalm. David is reigning in power, but only because of what the Lord has done. Nothing is because David is so great -- it's because God is so great, and David's power is rooted in that. Remove God, and David would fall.
It's a fine line to walk as we try and recall this. God sets us in places to fulfill our calling, gifting us with particular gifts and skills, and through the work of the Holy Spirit, we are called to obey and to serve. I think we should take pride in a job well done. But let us not forget the true source of our gifts, the true source of our life. It's not due to us that the world keeps spinning and that there's food on the table -- that's a gift from God, and may we join with David and sing our praises to God.