Today being the nineteenth day of the year, it is high time we meditated on some lines from Ps 19:
The heavens are telling the glory of God;
and the firmament proclaims his handiwork.
Day to day pours forth speech,
and night to night declares knowledge.
There is no speech, nor are there words;
their voice is not heard;
yet their voice goes out through all the earth,
and their words to the end of the world.
The idea here is that the universe around us speaks in a wordless manner about the glory of God -- his majesty, his goodness, his power, his wisdom. This has been a favorite theme of philosophers throughout history, as they reflected upon the nature of the physical universe and the evidence it provides for the existence of a creator.
Romanian Orthodox theologian Dumitru Stăniloae writes about the rationality and intelligibility of the universe as a demonstration of its origins:
We consider that the rationality of the cosmos is a testimony to the fact that it is the product of a rational being, because rationality, as an aspect of reality ordered to being known, would be inexplicable apart from a conscious rationality which knows it from the moment of its creation or even from before its creation, and which knows it concomitantly with its preservation in existence. On the other hand, the cosmos itself would be meaningless along with its rationality if human reason were not also given so as to know it on the basis of its rationality (Teologia Dogmatică Ortodoxă, vol. 1, p. 10).
In other words, the idea is this: the rationality and intelligibility of the universe is a testament to its origins in a greater Intelligence or Rationality which created it. The fact that we can know the world, the fact that our categories of understanding can latch onto the things in the world so that we can have genuine known of them, speaks to the fact that the world was created by a Rational Intelligence in some ways similar to our own. There would be no explaining nor expecting the intelligibility of the world otherwise; after all, why should the world be capable of being known, if God did not exist? On other hand, the rationality of the universe would be utterly meaningless if human beings did not also exist in order to know it.
Thus, for Stăniloae, there is an order to this world we live in. The created order is rational and intelligible because it has its origins in the creative power of a Rational Mind, whereas it finds its fulfillment in being known and understood by rational human persons. Moreover, through the knowledge of the intelligible order, the human person likewise comes upon knowledge of its Creator, and thus comes into contact with God. In this way, the world becomes a medium for interpersonal dialog between God and human persons:
Thus, the world as object is just the medium for a dialog of thought and loving deeds between the supreme rational Person and rational human persons, just as between the latter themselves (Teologia, vol. 1, p. 21).
This is what David says in the psalm, too: the heavens and the rest speak about the glory of God, and invite the human person into fellowship with her Creator. Above everything, the meditation of the grandeur of God in light of his created order leads one to trust in him for everything:
Let the words of my mouth and the meditation of my heart
be acceptable to you,
O LORD, my rock and my redeemer.
God alone, the Creator of absolutely everything that exists in this world, can be our hope and a source of stability and our savior in times of trouble.