What Preoccupies your Mind?

I was very challenged reading this just now (Tim Keller, Romans For You):

Those who live according to the flesh have their minds set on what the flesh desires; but those who live in accordance with the Spirit have their minds set on what the Spirit desires.

Romans 8.5

How do we overcome sin with the Spirit?... The people who do this are those who “have their minds set on what the Spirit desires” (8: 5). Paul says that the connection between living and thinking is a tight and close one. Literally he says: “For those being according to the flesh mind the things of the flesh, but those being according to the Spirit mind the things of the Spirit.” In other words, whatever you have set your mind on shapes your lifestyle and character. What does it mean to “mind” something or “set the mind”? Even in English, when the word “mind”is used as a verb, it has a stronger meaning than simply “to think about.” It means to focus intently on something, to be preoccupied with something, to have the attention and the imagination totally captured by something.

The twentieth-century Archbishop of Canterbury William Temple once said: “Your religion is what you do with your solitude.” In other words, wherever your mind goes most naturally and freely when there is nothing else to distract it—that is what you really live for. That is your religion. Your life is shaped by whatever preoccupies your mind. The overcoming of sin in our lives begins in our minds; and victory over sin is only ever the result of having minds set on the Spirit.