Our health depends on wise nutrition. The food we eat is assimilated into our bodies and becomes our nails, skin cells, and blood. In the same way, we are actually becoming—emotionally and spiritually—what we put into our minds. Proverbs 23:7 is the biblical version of you are what you eat. It says, “For as he thinks in his heart, so is he.”
What we read and view has a determining effect on us, and what our children are taking into their minds will determine what they become. Many children and adults have a high-fat mental diet that’s heavy in “screen time.”
It’s easy for any of us to “catch” the philosophy of the world by what we’re reading, watching, or hearing. But the Bible says, “Whatever things are true . . . noble . . . just . . . pure . . . lovely . . . of good report, if there is any virtue and if there is anything praiseworthy, meditate on these things” (Philippians 4:8).
People who feed their minds with lots of entertainment develop lazy minds. When we watch too many movies and too much television, we’re letting other people do our thinking for us. Those who feed their minds on a steady diet of celebrity magazines can become shallow. People who feed their minds on pornography become sexually immoral in their thoughts and behavior.
But what of those who feed their minds on quality literature, solid educational materials, truly relevant information, and regular Bible study? They become wise and sought-after leaders. Romans 8:5 says, “Those who live according to the flesh set their minds on the things of the flesh, but those who live according to the Spirit, the things of the Spirit.”
The secret of a healthy mind is the retention and meditation of Scripture. In his book Your Inner You, Pastor Leslie Flynn tells about Dr. Oscar Lowry, author of the book Scripture Memorizing for Successful Soul-Winning. Lowry entered Christian service as a young man with an undisciplined mind. Thinking he could not memorize Scripture, he filled the flyleaf of his Bible with references useful for counseling and evangelism, but it proved awkward to stop his conversations long enough to track down the right verse. Finally he determined to succeed at Scripture memory.
He rose early and chose a seemingly difficult passage, Romans 10:9-10. He paced the room, saying to himself, “I will do this thing.” He struggled with this passage for half an hour, but finally succeeded in memorizing it completely. The next morning, he reviewed and reinforced those verses in his memory, then added a new one. He kept reviewing his chosen passages and adding new ones until it dawned on him one day that he could repeat 100 verses without looking in his Bible.
By the end of his life, he had learned over 20,000 verses, and he could locate each by chapter and verse without his Bible. No wonder his Christian life was full of joy, his mind full of wisdom, and his evangelistic efforts full of success.
What if I came to your house today, knocked on your door, walked into your kitchen, and opened the door of your mind? What if I could peer into your brain? In a sense, I could do that by noticing the materials on the coffee table, the channels showing on the television, the DVDs scattered near the entertainment system, the books beside your bed, or the magazines under it. By observing how you fed your mind, I’d know a lot about your spiritual health.
Someone once said, “You are not what you think you are; but what you think, you are.” Let’s clean out the mental fridge and start stocking it with nourishment that befits those with the mind of Christ.
Take Thou our minds, dear Lord, we humbly pray,
Give us the mind of Christ each passing day;
Teach us to know the truth that sets us free;
Grant us in all our thoughts to honor Thee.
—William Foulkes, 1918
 Adapted from Leslie B. Flynn, Your Inner You (Wheaton: Victor Books, 1984), 60.