Controlling your thoughts is not magic or mind over matter. Your thoughts are powerful, but they are not all-powerful. We usually place too little emphasis on our thoughts. Taking control of your thoughts will, over time, change your feelings and even your circumstances.
I learned basic computer programming as a senior in high school—using the old eighty-column paper punch cards. If one little hole was punched wrong, the output would be meaningless. We were told “garbage in, garbage out.”
To bring your thoughts under control, take care of the hardware of your mind. Your brain needs water, healthy food, exercise, and rest.
Put a strong filter on the input your mind receives. Decrease or eliminate input that is anxiety-producing, ungodly, or negative. Feed your mind daily input that is encouraging, godly, uplifting, and positive.
And do a reboot, a software update on your thoughts. Choose to focus on the truth, on things you can change, and on what God says about the situation.
As you care for your mind’s hardware, input, and software, your thoughts and emotions—the output your mind produces—will better correspond with “these things” Paul encourages us to think about.