Is abortion a natural part of natural selection in nature or are wild animals considered murders when killing/naturally selecting their young as well as humans?I'm not sure how prevalent abortion is among wild animals. I would assume it does happen. However, this would not be considered "murder." That is because animals don't have a rational soul like human beings do. Their actions are motivated by instinct, and survival, and natural processes in their bodies. They do not have the ability to contemplate, or judge right from wrong. They do not have a conscience. God's moral laws do not apply to them. So, they cannot commit sins like murder, or stealing, or anything else that would be contrary to God's moral laws. Instead, we would simply say that they are being animals.
Also, "I always thought of God as ruler of the universe and creator of all things. Therefore, how much power does Lucifer have?God has tremendous power over Lucifer. But, the devil still has the power to lure mankind away from God. However, this is not so much due to his power as it is due to the fall of mankind. With the first sin of Adam, mankind fell from a life of grace. Now, his human nature is disposed to sin as it yearns for good in all the wrong places. The devil simply takes advantage of this. Of course, this is not to downplay the power of the devil. He is still an angel, and he still has the power to make himself very real in the lives of human beings, just as real as the angel Gabriel was to Mary.
St. Michael the Archangel...pray for us!!
I believe all people are inherently good because God would not make evil. So, I believe that people are disruptive and commit crimes because of, basically, lack of a psychiatrist=medication for illnesses, chemical imbalances, or an educated person to discuss issues. So, why does evil exist?Although sinful actions can be attributed to all of the factors you mentioned, at the heart of the matter is the reality of free will and original sin. This are the more fundamental causes of evil in the world.
God, in desiring that man would love Him for man's own sake, had to consequently grant man a will that was free. God's relationship with man would not be out of love if He forced man to be in relationship with Him, or coerced man into it. However, granting man free will has the necessary and unfortunate result of making it possible for man to turn away from God. If man has the power to say "Yes" to God, he also has the power to say "No." When he says "No" he sins and evil is brought into the world.
Is it possible for world peace to exist without the battle of good and evil while still maintaing the knowledge of good and evil?The battle of good and evil will always be with us...that is, until Jesus Christ comes again in glory, rids the entire world of evil, and makes all things new. On that day, there will only be peace, and goodness, and love.
The study of what will take place at the end of time is called eschatology. If you would like to learn more about this subject, go here. For more information on evil, go here.