The secular view of sin and evil seems almost absurd the moment it is removed from the self-centered, pleasure-seeking environment that sustains and encourages it.
Sin is obvious in the external actions of humanity throughout history and it would be lovely if we could gather up all the evil people and put them together on one island, leaving them to self-destruct in their collective sinfulness.
But that is not possible because sin is also deeply psychological and emotional. The line that separates good from evil is not out there somewhere, but inside the heart. It is cast down the center of my heart and yours.
The battle is within. The question is, are we willing to fight the battle?
Excerpted from Rediscover Catholicism by Matthew Kelly, page 158