For the creation waits with eager longing for the revealing of the sons of God. (ESV)
Mankind has always had a relationship with God's creation. In the first chapter of Romans Paul describes Creation as being the very thing that declares God's glory. Man saw God's glory revealed in Creation, but instead of worshiping the Creator, man worshiped the Creation. As a result man is under God's judgement and without excuse.
To this day we have an issue with mankind treating the Creation as if it is the thing to be worshiped. Many godless people who want nothing to do with serving and worshiping a Creator are consumed with serving and even worshiping the Earth. The fact that they are missing is that Creation waits with eager longing for the revealing of the sons of God. Creation longs for God. Man should follow.
Creation was subjected to frustration as man fell into sin in the Garden. Earth's first couple, Adam and Eve, were in a place of paradise; Eden. They had all that they could have wanted. The garden easily produced all that was needed for the first man and woman to eat. Adam sinned against God and the ground was cursed.
No longer would the ground easily produce what Adam wanted. He would be forced to labor for the produce that would be needed for his sustenance. Paul is telling us in Romans 8:19 that Creation itself longs for a day when God will reveal the sons of God. When will this happen? When God restores all things. God's glory will return his creation back to its original glorious state.
Creation is looking forward to God's revealing glory. Rather than us worshiping Creation, we should join Creation in worshiping God and anxiously looking forward to His glory.