The heavens declare the glory of God,
and the sky above proclaims his handiwork.
Day to day pours out speech,
and night to night reveals knowledge.
There is no speech, nor are there words,
whose voice is not heard.
Their voice goes out through all the earth,
and their words to the end of the world.
Thus Psalm 19.
I think there are two basic models for understanding this sort of text. On the one hand, there is the model which sees creation as a brute fact - something that is just there - from which it can be inferred that there is a God, and that he is glorious. This approach leads to cosmological and teleological arguments. On the other hand, there is the model which sees creation as communicative, as something that speaks and sings the glory of God. This approach leads to less arguments, and more mysticism.
It seems to me that Psalm 19 very definitely presents the latter approach to creation. The creation is not dumb, but speaks.
Our post-Enlightenment worldview does not prepare us well for this. We are expecting to be subjects approaching a world make up of objects. We are the active ones, and everything else is meant to be more or less passive. But this subject-object epistemology breaks down when faced with the communicative power of creation. Creation speaks - not of its own resources, but God speaks through it. We live in an inter-subjective universe; we are always in the presence of the word of another Person.
In practice, that means less arguments from creation and more marvelling at creation. It means that the feeling of wonder at the night sky matters, perhaps more than all the evidence of God that can be culled from philosophy. There is no getting away from the voice of God.