The creation is nowhere defended in scripture. It is presented as a fact, a nail pounded deeply into the hardest of wood. Hanging from this nail are tremendous truths – one of which is seen in Psalm 8.
God is the master creator of all things. He set everything into place. Nothing came about by random chance and the fact of God’s sovereignty is seen by the praise of the weakest in the face of the strongest (children and infants vs. foe and avenger).
And yet, this sovereign God has placed all His creation under the rule and authority of mankind, exalting this being, though also created and lower in status than the angels, to a position second only to God.
For this blessing, the Psalmist praises God.
But the importance of the Psalm has to do with the status of mankind. We are not just a piece of the cosmos. We are not just another type of being. We are different, superior, and in charge. But, of course, only if God is the creator. If He is not, we have no more moral authority than any other living thing in nature. We cannot claim authority because we are bigger or smarter or more powerful. And if we do so, we justify those of our own species who would oppress us because they are bigger, smarter, and more powerful.
God being creator is hugely important to our moral well-being, and His placement of us in charge should lead us all to praise His majestic name.