So in a sense, attributing eternity/timelessness to God is born out of dissatisfaction and disillusionment with the cyclical, transformative nature that seems to pervade in our universe? A want of having something permanent? Does this imply in some sense a rejection of the universe and of nature? Of viewing those things as "bad" or perhaps at least "not particularly good?"
Change does seem to be a hard thing for us humans to wrestle with. With that, I can see how the idea of a changeless thing has appeal.
Yes, I would say that dissatisfaction and disillusionment with the apparently ephemeral or fleeting nature of life is definitely a determining factor.
However this need not always lead to a longing for an eternal "god" or "gods" in the sense of 'concious being(s)'. Buddhism and Taoism are both attempts to solve this same dilemma of impermanence and dissatisfaction with change from explicitly non-theistic/atheistic perspectives. So it can take a theistic or a non-theistic form.
In terms of rejecting nature or the universe, this may be the case in some religions and philosophies (ie Gnosticism) but it is not in accordance with Catholic theology. We do not view the universe or nature as "bad" or even "not particularly good". We actually believe that God is "in" everything and pervades His creation, with His Divine Essence and power keeping everything in existence. So creation is good, the body and material reality is good, the universe is good.
Creation, according to Catholic thought, is a "self-communication" of God. It is essentially a means by which the Eternal God, out of sheer goodness and love, communicates Himself to other beings that He has created. The creation is therefore made for the glory of God and will "return" to Him. I would view it sort of like the current of the sea. It flows out from God, eternity, into creation in time and then in the natural order flows back to Him again. This is how many Catholic mystics understood it, ie:
"...
God is a flowing and ebbing sea which ceaselessly flows out into all his beloved according to their needs and merits
and which flows back with all those upon whom he has bestowed his gifts in heaven and on earth, together with all they possess or are capable of.
This is that Wayless Being which all fervent interior spirits have chosen above all things, that dark stillness in which all lovers lose their way. If we could prepare ourselves through virtue in the ways I have shown,
we would at once strip ourselves of our bodies and flow into the wild waves of the Sea, from which no creature could ever draw us back...."
- Blessed John of Ruysbroeck (1293 – 1381), The Spiritual Espousals
So its not about "rejecting" the world so much as "returning" to its ultimate source.
God is expressing Himself through creation much like an artist expresses Himself through a painting or a novel. However the difference is that an artist or a novelist creates inanimate, abstract objects that have no inherent reality. When God creates, He creates
realities including free-willed, concious beings like ourselves. In the end, while the piece of art is beautiful and communicates something of the artist himself (being an expression of Him) it "isn't" the artist Himself. Therefore, human beings being created in the image of the artist, seek not only the art but the artist Himself and Union with Him.
Therefore, we believe that creation is not
perfect. This might seem akin to "not particularly good" but it isn't. For while the universe is "good", it is not "perfect" in the sense that it cannot possibly fulfil all of our desires. Since we are a union of body and soul, it naturally follows that the material (if one adheres to such a belief in the first instance) cannot hope to satisfy all the urgings of the human spirit. If it could, then we would surely not have created ideas of "afterlives" and "disembodied" souls in the first place. To live in the world is to experience both sadness and joy. No one can find lasting happiness from purely material things in an impermanent world marked by constant change.
That is why the early Christian ascetics who took to the deserts of Egypt and Syria in the third century AD, fleeing the pleasures of the Roman Empire, sought after something they called "
apatheia" which translates as "a state of
imperturbable calm", a joy and serenity not marked by the changeability found in the world, a 'happiness' that never changes and lasts forever. The point is though, since God is "in" the world we can experience something close to this ultimate "eternal bliss" while still in this present world, through Union with God. So there is no radical separation between an "evil" material world and a "good" spiritual one as in some forms of Gnosticism. Union with God is something to be pursued in the here and now.
The Church officially teaches that God created the universe in a "state of journeying" towards fulfilment, the same fulfilment that the human spirit longs for as well: "that God might be All in All":
http://www.vatican.va/archive/ccc_css/archive/catechism/p1s2c1p4.htm
III. "THE WORLD WAS CREATED FOR THE GLORY OF GOD"
293 Scripture and Tradition never cease to teach and celebrate this fundamental truth: "The world was made for the glory of God."134 St. Bonaventure explains that God created all things "not to increase his glory, but to show it forth and to communicate it",135 for God has no other reason for creating than his love and goodness: "Creatures came into existence when the key of love opened his hand."136 The First Vatican Council explains:
This one, true God, of his own goodness and "almighty power", not for increasing his own beatitude, nor for attaining his perfection, but in order to manifest this perfection through the benefits which he bestows on creatures, with absolute freedom of counsel "and from the beginning of time, made out of nothing both orders of creatures, the spiritual and the corporeal. . ."137
294 The glory of God consists in the realization of this manifestation and communication of his goodness, for which the world was created. God made us "to be his sons through Jesus Christ, according to the purpose of his will, to the praise of his glorious grace",138 for "the glory of God is man fully alive; moreover man's life is the vision of God: if God's revelation through creation has already obtained life for all the beings that dwell on earth, how much more will the Word's manifestation of the Father obtain life for those who see God."139 The ultimate purpose of creation is that God "who is the creator of all things may at last become "all in all", thus simultaneously assuring his own glory and our beatitude."140...
310 But why did God not create a world so perfect that no evil could exist in it? With infinite power God could always create something better.174 But with infinite wisdom and goodness God freely willed to create a world "in a state of journeying" towards its ultimate perfection [eternity]. In God's plan this process of becoming involves the appearance of certain beings and the disappearance of others, the existence of the more perfect alongside the less perfect, both constructive and destructive forces of nature. With physical good there exists also physical evil as long as creation has not reached perfection.175
So while we would argue that as it is now the material universe cannot satisfy us entirely, this is not a rejection of the world or a denunciation of it as "evil". Like us, it too is "progressing" towards perfection in God. It will "flow" back into Him from whence it came, so to speak.