We all despise the man who demands continued assurance of his own virtue, intelligence or delightfulness; we despise still more the crowd of people round every dictator, every millionaire, every celebrity, who gratify that demand. Thus a picture, at once ludicrous and horrible, both of God and of His worshippers, threatened to appear in my mind. The Psalms were especially troublesome in this way—”Praise the Lord,” “O praise the Lord with me,” “Praise Him.” … It was extremely distressing. It made one think what one least wanted to think. Gratitude to God, reverence to Him, obedience to Him, I thought I could understand; not this perpetual eulogy. …

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 honour. I had never noticed that all enjoyment spontaneously overflows into praise

The world rings with praise—lovers praising their mistresses, readers their favourite poet, walkers praising the countryside, players praising their favourite 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. … Except where intolerably adverse circumstances interfere, praise almost seems to be inner health made audible. …

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. …

To see what the doctrine really means, we must suppose ourselves to be in perfect love with God—drunk with, drowned in, dissolved by, that delight which, far from remaining pent up within ourselves as incommunicable, hence hardly tolerable, bliss, flows out from us incessantly again in effortless and perfect expression, our joy no more separable from the praise in which it liberates and utters itself than the brightness a mirror receives is separable from the brightness it sheds. The Scotch catechism says that man’s chief end is “to glorify God and enjoy Him forever”. But we shall then know that these are the same thing. Fully to enjoy is to glorify. In commanding us to glorify Him, God is inviting us to enjoy Him.

—C. S. Lewis
Reflections on the Psalms, 89–96.