I love watching my kids. One of the reasons is that they teach me so much about myself.

My son gets really into things. For a while he’ll be into Star Wars. Everything will be Star Wars. Every stick is a light saber. He just breaths Star Wars, and all that he talks about is Star Wars. Then one day he’s on to the next thing. A month or so ago it was Harry Potter. He was sitting next to his uncle and talked incessantly for the whole time about Harry Potter. For him the world reduced to all Harry all the time. He sees the whole world through the filter of what he’s spending so much time thinking about.

To a slightly lesser extent I do the same thing, although not with Star Wars and Harry Potter. A significant part of my job is programming, and when I am working on particularly intractable technical challenges in my work I get pretty intensely focused on that. Soon I start to dream in arrays and curly braces. That which I am focused on so intently fills my world and my thoughts, even when I am asleep.

I don’t have any idea if most other people focus intently on things as much as my son and I do. I know quite a few people who do this to some extent or other. Maybe its the things they worry about, finances, or their job, or other concerns about relationships and life. For all of us, though, it is true that the things that we spend our time thinking about are the things that come out in our conversations, that will fill our thoughts at random moments, that will show others what is important enough to us that it holds our attention.

People fill their minds with all sorts of things. TV shows, music, books, activities, sports, pictures, jokes… The things they put into their minds are the things that come out of them. The music people listen to, the shows they watch, the books they read all impact the way we see the world. Advertisers know this, of course, which is why we have a huge marketing industry. But so many of us act like we can fill our minds with anything we want and it doesn’t matter.

Jesus said “The eye is the lamp of the body; so then if your eye is clear, your whole body will be full of light. But if your eye is bad, your whole body will be full of darkness. If then the light that is in you is darkness, how great is the darkness! No one can serve two masters; for either he will hate the one and love the other, or he will be devoted to one and despise the other” (Matthew 6:22-23 NASB)

The things that I put in my mind, the things that I am dwelling on, reflect my values and priorities. They reflect what I treasure. Some of these things might be evil, and I need to protect myself, my heart and my mind, from many of the images and messages our culture broadcasts to us every day. Many of the things I fill my mind with aren’t inherently evil though. There isn’t anything wrong with interesting technical challenges, or with Star Wars or Harry Potter. But if they are my obsession, they start to take over my thoughts and push out other things that are more important. I can’t serve two masters. That principle doesn’t just apply to money, although that is the example Jesus gave in his talking about treasure in Matthew 6. Money is the idol that most people, especially in our society worship, and it is very relevant in our context to warn against the worship of that kind of treasure. But even having overcome that trap, we can still fall for filling our minds and hearts with treasures other than the One who matters.

Guard your heart and mind. What you put into them is what you will treasure, and what you will get out of them. In the time that you have a choice what you will put into your mind, use that time to build your relationship with God, rather than your relationship with the latest reality show participant or fictional TV character, or your favorite topic other than God, or whatever it is you have a tendency to fill your mind with. If we aren’t intentional about it, we can be sure someone else will make sure we are filling our mind and heart with anything but God. And then, even if those things aren’t evil in themselves, for us they become a block over which our walk with God stumbles.

“The kingdom of heaven is like a treasure hidden in the field, which a man found and hid again; and from joy over it he goes and sells all that he has and buys that field.” (Matthew 13:44)

What do you treasure?