Beyond the singing that I highlighted in that text, we also talked a lot about gratitude. Here's more of the context of that passage:
Let the peace of Christ rule in your hearts, since as members of one body you were called to peace. And be thankful. Let the message of Christ dwell among you richly as you teach and admonish one another with all wisdom through psalms, hymns, and songs from the Spirit, singing to God with gratitude in your hearts. And whatever you do, whether in word or deed, do it all in the name of the Lord Jesus, giving thanks to God the Father through him.
There's something that interrupts you in the concision of the short imperative: "And be thankful."
A few years ago, I suggested that a goal of Christian spiritual formation is to cultivate a "Eucharistic identity." The word "Eucharist" comes from the Greek word εὐχαριστία (eucharistia) which means "thanksgiving."
A "Eucharistic identity," then, is an identity grounded in thanksgiving and gratitude. A "Eucharistic identity" experiences life as grace, as the Greek word for grace--χάρις (cháris)--is the word for gift, that which prompts thanksgiving, gratitude and rejoicing.
Cháris prompts eucharistia, and eucharistia transforms experience into cháris. This is the round of a Eucharistic identity, a life shaped by "be thankful."
