How would you describe someone who lies to you? Who stirs you up? Who makes you anxious and afraid? Who whispers that you’re not good enough? Who urges you to suspect the worst of others? Who tricks you into doing things you’ll regret? 

Believe it or not, that’s exactly what our own mind does to us every single day.

The band The National puts it bluntly: “Your mind is not your friend. It takes you by the hand / And leaves you nowhere.” They’re not wrong.

Ancient Greek philosophers also understood this tension. As much faith as they had in the power of “ruling reason,” they were also deeply suspicious of the mind’s tricks. That’s why Epictetus urged his students to “put every impression to the test.” Marcus Aurelius filled his Meditations with a running dialogue with himself — questioning his own assumptions, challenging his impulses, debating with his thoughts so he wouldn’t be led astray by them.

And this is the work we must do as well. Our minds can be brilliant partners. They can help us plan, create, imagine, and reason. But they can also lead us off the rails. They’re not always reliable. If we simply follow every thought we think, we’ll end up lost, anxious, bitter, or slaves to destructive patterns.

The Biblical Call to Renew the Mind

This is why the Bible doesn’t just warn us about the dangers of our thinking — it also calls us to train our minds. Paul puts it this way in Romans 12:2:

“Do not be conformed to the pattern of this world, but be transformed by the renewing of your mind. Then you will be able to test and approve what God’s will is — his good, pleasing and perfect will.”

Notice the language: be transformed — not by trying to will ourselves into holiness, but by the renewing of the mind. This is an ongoing -- in fact, lifelong -- process. It’s a daily practice. Just like the Stoics urged their students to test every impression, Christians are called to continually realign their thinking with God’s truth.

The renewal of the mind means catching lies and replacing them with God’s promises. It means noticing when fear or self-condemnation take over, and choosing instead to meditate on grace and peace. It means recognizing when suspicion, lust, or bitterness creep in, and learning to redirect our focus toward love, gratitude, and trust.

The Work in Front of Us

So let’s be clear: your mind is not your enemy — but it’s not always your friend either. It must be trained, guided, and renewed. Left on its own, it will wander into anxiety, resentment, and distraction. But when brought under God’s truth, it can become a powerful ally in living with wisdom, peace, and joy.

This is the work before us: to pay attention to our thoughts, to test them, to reject what is false, and to anchor ourselves in what is true. As Paul says elsewhere, we are to “take every thought captive to obey Christ” (2 Corinthians 10:5).

It won’t happen overnight. But every day, with every thought we notice and redirect, we take another step toward freedom.