7 And the peace of God, which surpasses all understanding, will guard your hearts and your minds in Christ Jesus. 8 Finally, beloved,[a] whatever is true, whatever is honorable, whatever is just, whatever is pure, whatever is pleasing, whatever is commendable, if there is any excellence and if there is anything worthy of praise, think about[b] these things. 9 Keep on doing the things that you have learned and received and heard and seen in me, and the God of peace will be with you. Philippians 4: 7-9 (NRSV)
Matthew 12:43-45: 43 “When the unclean spirit has gone out of a person, it wanders through waterless regions looking for a resting place, but it finds none. 44 Then it says, ‘I will return to my house from which I came.’ When it comes, it finds it empty, swept, and put in order. 45 Then it goes and brings along seven other spirits more evil than itself, and they enter and live there; and the last state of that person is worse than the first. So will it be also with this evil generation.”
We can’t just stop thinking wrong thoughts and leave our minds empty. As Jesus pointed out in the passage from Matthew, if we don’t fill our emptiness with something, when the evil spirit returns, he will bring companions with him, take up residence and our end is worse than the beginning. So, what do we do? Paul suggests that we focus on the things he mentions above. Think honorable, just, pure, commendable thoughts. We need to put each thought to a test to see if it fits in one of the categories he lists. If not, we need to cast out those rebellious/evil thoughts. We are not alone in this battle, we have the peace of God that guards our hearts and our minds. But we must keep practicing “right ” thinking to keep the peace of God.