C. S. Lewis was bothered by the fact that the Psalms repeatedly call us to praise the Lord. Then he had an epiphany. From Lewis's Reflections on the Psalms:

But the miserable idea that God should in any sense need, or crave for, our worship like a vain woman wanting compliments, or a vain author presenting his new books to people who never met or heard of him, is implicitly answered by the words, "If I be hungry I will not tell thee (Psalm 50:12). Even if such an absurd Deity could be conceived, He would hardly come to us, the lowest of rational creatures, to gratify His appetite. I don't want my dog to bark approval of my books. Now that I come to think of it, there are some humans whose enthusiastically favorable criticism would not much gratify me.

But the most obvious fact about praise — whether of God or anything — strangely escaped me. I thought of it in terms of compliment, approval, or the giving of honor. I had never noticed that all enjoyment spontaneously overflows into praise unless (sometimes even if) shyness or the fear of boring others is deliberately brought in to check it. The world rings with praise — lovers praising their mistresses, readers praising their favorite poet, walkers praising the countryside, players praising their favorite game — praise of weather, wines, dishes, actors, motors, horses, colleges, countries, historical personages, children, flowers, mountains, rare stamps, rare beetles, even sometimes politicians or scholars. I had not noticed how the humblest, and at the same time most balanced and capacious minds, praised most, while the cranks, misfits, and malcontents praised least. The good critics found something to praise in many imperfect works; the bad ones continually narrowed the list of books we might be allowed to read. the healthy and unaffected man, even if luxuriously brought up and widely experienced in good cookery, could praise a very modest meal: the dyspeptic and the snob found fault with all. Except where intolerably adverse circumstances interfere, praise almost seems to be inner health made audible. Nor does it cease to be so when, through lack of skill, the forms of its expression are very uncouth or even ridiculous. Heaven knows, many poems of praise addressed to an earthly beloved are as bad as our bad hymns, and an anthology of love poems for public and perpetual use would probably be a sore a trial to literary taste as Hymns Ancient and Modern. 

I had not noticed, either, that just as men spontaneously praise whatever they value, so they spontaneously urge us to join them in praising it: "Isn't she lovely? Wasn't it glorious? Don't you think that magnificent?" The Psalmists in telling everyone to praise God are doing what all men do when they speak of what they care about. My whole, more general, difficulty about the praise of God depended on my absurdly denying to us, as regards the supremely Valuable, what we delight to do, what indeed we can't help doing, about everything else we value. 

I think we delight to praise what we enjoy because the praise not merely expresses but completes the enjoyment; it is its appointed consummation. It is not out of compliment that lovers keep on telling one another how beautiful they are; the delight is incomplete till it is expressed. It is frustrating to have discovered a new author and not to be able to tell anyone how good he is; to come suddenly, at the turn of the road, upon some mountain valley of unexpected grandeur and then to have to keep silent because the people with you care for it no more than for a tin can in the ditch; to hear a good joke and find no one to share it with (the perfect hearer died a year ago*). This is so even when our expressions are inadequate, as, of course, they usually are. But how if one could really and fully praise even such things to perfection — utterly "get out" in poetry, or music, or paint the upsurge of appreciation which almost bursts you? Then indeed the object would be fully appreciated and our delight would have attained perfect development. The worthier the object, the more intense this delight would be. If it were possible for a created soul fully (I mean, up to the full measure conceivable in a finite being) to "appreciate," that is to love and delight in, the worthiest object of all, and simultaneously at every moment to give this delight perfect expression, then that soul would be in supreme beatitude.