Psalm 104 is a meditation on Genesis 1. It is blatantly obvious as you can see how the psalm is broken up into seven units that parallel the seven creation days in Genesis 1.
Psalm 1 makes manifest the purpose of Genesis 1--to provoke praise to God! It (Gen. 1) is not intended to be a rigorously detailed scientific document. Gen 1 is meant to inspire awe in his creatures. We are to learn of His power and ongoing providence over nature. It is actually Hebrew poetry to be savored (Even in the English, notice the poetic parallels between Day 1 & 4, 2 & 5, 3 & 6.) Indeed, the universe declares His glory (Ps. 19.1, making manifest His nature (Rom. 1:19-20).
"May my meditation be pleasing to him as I rejoice in the Lord," (Ps. 104:34).
My joy pleases God. Said another way, if I seek to please Him in every way (Col. 1:10; 2 Cor. 5:9), then I must vehemently seek my own joy. God wants no sullen Christians. This is not mere petty happiness, which ebbs and flows based on circumstances, rather it is "in the Lord". We are to be like God in our joy. He too savored the beauty of His work, his creation, the demonstration of His glory (104:31): "It is good," (Gen 1), and then ceased His work in contentment. We have not reached our Sabbath rest yet (Heb. 4:9); but we can look at our lives, the work given to us in the Lord, and rejoice, saying "it is good."
I need to spend more time in meditation and observation of nature, that I too may say sincerely, "it is good", and more so, "He is good." As a church, we need to struggle more vigorously to enjoy Jesus, not fretting over small details and worries or the possibility that we may easily anger Him. To be sure, He has awful anger towards evil, but He is patient and gives grace to those in Christ. We need not fear. Fear kills joy.