And the most important piece of clothing you must wear is love. Love is what binds us all together in perfect harmony. And let the peace that comes from Christ rule in your hearts. For as members of one body you are all called to live in peace. And always be thankful.  Let the words of Christ, in all their richness, live in your hearts and make you wise. Use his words to teach and counsel each other. Sing psalms and hymns and spiritual songs to God with thankful hearts. 17 And whatever you do or say, let it be as a representative of the Lord Jesus, all the while giving thanks through him to God the Father. Colossians 3:14-17 (NLT)

The word translated “rule” is a Greek word that describes an official at an athletic event, similar to a present-day umpire. People ask, “Should I move? Should I take that job? Should I marry him?” I often answer with a question: “What does your heart tell you? If you’re walking with the Lord, the peace of God will be an umpire in your heart, calling Safe! or Out!”
Women, when he asks you to marry him, don’t say yes if there isn’t a deep sense of peace in your heart. “You just have cold feet,” he’ll say. But I suggest to you it is much more than that. I suggest it is God working deep within your soul, whispering, “Don’t do it.” Don’t move, gang, without the peace of God umpiring and ruling in your heart.

The flip side is the man who says he has peace about divorcing his wife.

“Really?” I ask. “Why?”

“Well, I’ve prayed. I’ve fasted. I’ve sought God and I have peace.”

In response, I’ll say, “Jonah had peace, too. God told him to go to Nineveh, but he disobeyed and headed in the opposite direction to Tarsus. And guess what. There was a boat waiting for him because there’s always a boat waiting to take you in the opposite direction of God’s will—compliments of Satan. Such peace had Jonah about disobeying God that he even slept right through a storm.

Listening to our hearts can’t be the only criteria for determining God’s will because Jeremiah 17:9 says the heart is deceitful above all things and desperately wicked. That’s where the Word comes in.

The Word is the final authority. When someone says they have peace about something that contradicts the Word, you must look him in the eye and say, “You’re headed for a whale of a time. I don’t care what ship is ready to take you away, or how peaceful you feel in the hull of the boat. What you’re doing is contrary to the Word.”
Yes, the peace of God rules in your heart, but it will never contradict the wisdom of God as revealed in His Word.

Pastor Jon Courson commenting on Colossians 3:15-16