An act of the will (Colossians)

In Colossians 3:2, Paul challenges the people to set their minds on things above instead of things on earth.  What's important to notice in this challenge is that it's our responsibility to choose what we set our minds on.  The truth of the matter is that we could set our minds on all kinds of different things, but Paul says we should choose to set our minds on things that are above.  In other words, we can't be allowing ourselves to dwell on thoughts of jealousy, pride, hatred, and the like.  Those are things that come naturally to us; those are heart issues that we don't have to strive after.  That's why it's an act of the will to set our minds of the things of God.  How are you at accomplishing this?  Do you find yourself giving into the ambitions of the world, or do you see yourself constantly seeking to do the will of the Lord?