From the National Catholic Register:
Why is there so much war in the world?
This may seem strange, but it’s because people are hungry for the happiness of God, and try to get it in wrong ways.
If that sounds crazy, it’s because it is. Sin is basically crazy. Sin means putting yourself before God.
If God made us who created God?
What does God look like?
Why is the world here?
Why are we here?
Why are people bad to each other? (answers here)