21 To be lowly is to remain in a low estate, and to be meek is to not fight for oneself. We should exercise these two virtues in dealing with ourselves. To be long-suffering is to endure mistreatment. We should exercise this virtue in dealing with others. By these virtues we bear (not just tolerate) one another; that is, we do not forsake the troublesome ones but bear them in love. This is the expression of life.
These virtues are not found in our natural humanity but are in the humanity of Jesus. The fact that the virtues are mentioned here, before the oneness of the Spirit in v. 3, indicates that we must have these virtues in order to keep the oneness of the Spirit. This implies that in the uniting Spirit there is the transformed humanity, the humanity transformed by the resurrection life of Christ.