"For I consider that the sufferings of this present time are not worth comparing with the glory that is to be revealed to us. For the creation waits with eager longing for the revealing of the sons of God. For the creation was subjected to futility, not willingly, but because of him who subjected it, in hope that the creation itself will be set free from its bondage to corruption and obtain the freedom of the glory of the children of God. For we know that the whole creation has been groaning together in the pains of childbirth until now." (Rom 8.19-22 ESV)
The focus of this passage is the exact meaning of Paul's use of "creation". There isn't uniform agreement. Modern scholarship that I have consulted holds that the apostle is speaking of the physical universe, both animate and inanimate. As A. T. Robertson put it in his Word Pictures:
"The revealing of the sons of God (tēn apokalupsin tōn huiōn tou theou). Cf. 1Jo 3:2; 2Th 2:8; Col 3:4. This mystical sympathy of physical nature with the work of grace is beyond the comprehension of most of us. But who can disprove it?"
Our Wesleyan exegete, Adam Clarke, dismissed this understanding. However, at the conclusion of his remarks for Chapter 8 of Romans, he added the following:
"The restoration of the brute creation to a state of happiness has been thought by several to be the doctrine of Rom 8:19-25. In the notes on those verses I have given reasons against this opinion, and have proved that the Gentiles, and not the irrational part of the creation, are the persons of whom the apostle speaks; nor can any consistent interpretation be given of the place, if it be applied to the brute creation. But, although this doctrine is not contained in the above verses, it does not follow that the doctrine itself is not true. Indeed, there are several reasons which render the supposition very probable.
"1. The brute creation never sinned against God, nor are they capable of it, and consequently cannot be justly liable to punishment.
"2. But the whole brute creation is in a state of suffering, and partake of the common infirmities and privations of life, as well as mankind: they suffer, but who can say that they suffer justly?
"3. As they appear to be necessarily involved in the sufferings of sinful man, and yet neither through their fault nor their folly, it is natural to suppose that the Judge of all the earth, who ever does right, will find some means by which these innocent creatures shall be compensated for their sufferings.
"4. That they have no compensation here, their afflictions, labors, and death prove; and if they are to have any compensation, they must have it in another state.
"5. God, the fountain of all goodness, must have originally designed them for that measure of happiness which is suited to the powers with which he had endowed them; but, since the fall of man, they never had that happiness; and, in their present circumstances, never can.
"6. In reference to intelligent beings, God has formed his purposes in reference to their happiness on the ground of their rational natures. He has decreed that they shall be happy if they will, all the means of it being placed within their power; and, if they be ultimately miserable, it is the effect of their own unconstrained choice. Therefore his purpose is fulfilled, either in their happiness or misery; because he has purposed that they shall be happy if they please, and that misery shall be the result of their refusal.
"7. But it does not appear that the brute creation are capable of this choice; and it is evident that they are not placed in their present misery through either their choice or their sin; and if no purpose of God can be ultimately frustrated, these creatures must be restored to that state of happiness for which they have been made, and of which they have been deprived through the transgression of man.
"8. To say that the enjoyments which they have in this life are a sufficient compensation, is most evidently false; for, had not sin entered into the world, they would have had much greater enjoyments, without pain, excessive labor and toil, and without death, and all those sufferings which arise from its predisposing causes. Nor does it appear that they have much happiness from eating, drinking, and rest, as they have these only in the proportion in which they are necessary to their existence as the slaves of men. Therefore, allowing that they have even gratification and enjoyment in life, they have much less than they would have had had not sin entered into the world; and consequently they have been deprived of the greater portion of the happiness designed for them by their bountiful Creator.
"9. It is therefore obvious that the gracious purpose of God has not been fulfilled in them; and that, as they have not lost their happiness through their own fault, both the beneficence and justice of God are bound to make them a reparation.
"10. Hence it is reasonable to conclude that, as from the present constitution of things they cannot have the happiness designed for them in this state, they must have it in another."
I believe that Paul is speaking of the present state of affairs in the universe. Adam's sin in the garden of Eden did more than plunge mankind into estrangement with God; it further knocked all of creation out of kilter. Plants die and animals--on the food chain--kill each other off. Only the Day of Resurrection and Judgment/Restoration with "new heavens and a new earth" will restore things to the way they were before Adam decided to eat the forbidden fruit.