There are other created beings in the Universe, and there is no reason to believe that an Eternal God has ceased creating, just because he made the Earth. Since God seems to prefer creatures that have free will, it seems to be that one of the primary reasons God has allowed suffering to come to our planet is to provide the rest of the present and future Universe with an undeniable object lesson of the horrors of choosing to disobey God by rejecting His just and holy laws.
In a sense, God has allowed the sufferings that sin has brought to planet earth to be a shocking experiment, which all of the other sinless creatures scattered throughout the universe are allowed to watch and observe. The purpose of this experiment is to demonstrate clearly to every sentient being that God's commands, rules, judgments, principles and regulations are right and just and good, given for the benefit of all.
By looking upon the horror that humans have unleashed upon themselves, all the rest of God's creatures and angelic hosts have been given a powerful object lesson of how NOT to act! This of course will prove to be a great benefit to all those other planets and/or dimensions that have not followed our example of rebellion against God, but it is of course little comfort to US, who must endure this hellish mess!
Well, it is first helpful to remember that in the beginning, God made everything on Earth to be VERY GOOD. Also remember that God made our test to be very, very easy. So now we are forced to live out the bad choices of our ancestors. However, because God is VERY GOOD, He has given us this wonderful promise: "I know that you have suffered much, but I give you my Holy and Immutable Word: "I'm going to make it up to you! The little bit of trouble and sorrow you pass through now, you will esteem as nothing, compared to the glory, greatness and riches I will give you in Heaven! And that's my guaranteed promise!" Because the human race has had to endure the horrors of Hell, our God is going to make it up to us in many wonderful ways. Revelation 21:1-5
