“Legalism is helpless in bringing this about; it only gets in the way. Among those who belong to Christ, everything connected with getting our own way and mindlessly responding to what everyone else calls necessities is killed off for good—crucified.”
In order to fully understand this verse, it might be helpful to read the set of verses preceding this one, wherein Paul is putting things into perspective for his reader. He says — and this is a paraphrasing in the same version of The Message — But what happens when we live God’s way? He brings gifts into our lives, much the same way that fruit appears in an orchard—things like affection for others, exuberance about life, serenity. We develop a willingness to stick with things, a sense of compassion in the heart, and a conviction that a basic holiness permeates things and people. We find ourselves involved in loyal commitments, not needing to force our way in life, able to marshal and direct our energies wisely. For the believer, you do what you do (or don’t do) out of love, not out of fear. Doing it for any other reason is the wrong reason to do it and is a form of legalism.