"And above all these things put on charity (love), which is the bond of perfectness. And let the peace of God rule in your hearts" ~ Colossians 3:14, 15a"ABOVE all these things." If you will read Colossians 3:12 and 13, you will find Paul's list of Christian behavior patterns which we are to adopt. And then, having been changed from a Christ-hater to a love-slave of the Lord Jesus, Paul Says: "Above all these things put on love ..."
Love covereth. And after we have "put on love," we are to "let the peace of God rule in our hearts." Just putting on love once --- does not complete the operation. After that, minute by minute, we are to "let the peace of God" take over in our hearts first, and then it will inevitably be in command of our actions and our words.
We have already seen that our heart, as the Bible speaks of it, is far more than the seat of our emotions. It is the seat of our wills and thoughts as well. It is the "description" of our very characters. We are exactly what our hearts show us to be. And if we are to be obedient, we will ---
"... let the peace of God rule in our hearts ... and be ye thankful."