Hi:
Great question Greendawn.......
In the Catholic Tradition, all creation is considered to be by its very nature good including mankind. (Unlike what the JWs and other Protestant groups teach about human nature which is that it is by its very nature evil.) However, according to Catholic Tradition, we are wounded because of inherited sin but NOT inherently evil. This means that we can take good things and use them inappropriately and make them bad. Or, to put it another way, we can choose to act in a way that is inferior to the way that God wants us to act. But we can also choose to do good although many times that is not our first inclination.
In short, God wants us to participate in His life. That, according to Catholic Tradition, should be the goal of all Christians. We can choose to start living the life of God in this world if we want to, but Satan influences our culture and encourages us to make poor choices and do evil. By the way, often times we think of good and evil as being equal. However in Catholic Tradition evil is really more of a deficiency in something that was originally good. In other words, evil is a corruption of what is inherently good.
However, all is not lost. In the Catholic Tradition, the Lord gives us sacraments through the Church to give us the grace (think power) to choose to do good and to overcome our tendency to be attracted to sin. So through the ministry of the sacraments from the Church, the Lord has defeated Satan and evil, if we choose to be open to God's assistance. In this way, Jesus defeated Satan in that currently through the Church (known as Christendom which is Christ's Kingdom) and the sacraments that the Church administers, people can overcome their tendency toward sin and receive eternal life even now. This is a major defeat for Satan who wishes not just death for us but he also wishes eternal separation from God upon us as well.
Eventually, of course, Satan will be permanently imprisoned at the end of time according to Catholic Tradition and all people who choose what is good will have the privilege of living forever in the new heavens and new earth in the literal physical presence of God. There we will participate in the life of God to its fullest. Right now we merely have a foretaste of that life through the sacraments of the Church.
I hope that answers your question.
Jeff Schwehm