HOW does the existence of the Universe make those who do not worship God to be "without excuse"? &quot;For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who by their unrighteousness suppress the truth. For what can be known about God is plain to them, because God has shown it to them. For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made. So they are without excuse.&quot; (Romans 1:18-20, ESV)

The Apostle Paul here says that those who ignore God, who fail to worship him or give him thanks are without excuse because the Universe shows there is a Creator God with certain attributes, namely, that he is eternal and has a divine nature.
My question is, in what way(s) does the existence of the Universe plainly demonstrate the existence and nature of God?  Preferably, in your answer say what &quot;eternal power&quot; means, and show how the Universe demonstrates the eternal power of God?
My question seeks answers mainly from a Trinitarian perspective.  (If you answer from other perspectives please indicate this in your answer.  Thanks.)
St. Paul is evidently musing on themes in the book of Wisdom in Chapter 1 and beyond:

Wisdom 13:1-9 But all men are vain, in whom there is not the knowledge of God: and who by these good things that are seen, could not understand him that is, neither by attending to the works have acknowledged who was the workman: 2 But have imagined either the fire, or the wind, or the swift air, or the circle of the stars, or the great water, or the sun and moon, to be the gods that rule the world. 3 With whose beauty, if they, being delighted, took them to be gods: let them know how much the Lord of them is more beautiful than they: for the first author of beauty made all those things. 4 Or if they admired their power and their effects, let them understand by them, that he that made them, is mightier than they: 5 For by the greatness of the beauty, and of creation, the creator of them may be seen, so as to be known thereby. 6 But yet as to these they are less to be blamed. For they perhaps err, seeking God, and desirous to find him. 7 For being conversant among his works, they search: and they are persuaded that the things are good which are seen. 8 But then again they are not to be pardoned. 9 For if they were able to know so much as to make a judgment of the world: how did they not more easily find out the Lord thereof?

The logic is this: in recognizing objective beauty in something (to the extent, especially, of worshipping it), one of necessity must recognize the mind behind it, since beauty is only appreciable in a mind, and thus only authorable by it. Hence, for as long they do so and refuse to worship the Author of such beauty, they sin: &quot;for the first author of beauty made them all.&quot;
And if the author of beauty itself is greater, by definition, than the sum of all his creations, then &quot;his eternal power&quot; is evident, because it is far beyond - literally - anything we can conceive or imagine, and obviously lives with him, and so eternally.
The overall point is that all goes back to God, no matter what it is, good or bad; if you worship the good things He made, you are offending and robbing Him; if you worship the bad things, you are doing him a double offense and a double robbery.