We conclude, therefore, that a Christian lives not in himself, but in Christ and in his neighbor. Otherwise he is not a Christian. He lives in Christ through faith, in his neighbor through love. By faith he is caught up beyond himself into God. By love he descends beneath himself into his neighbor.
Martin LutherIt is the part of a Christian to take care of his own body for the very purpose that, by its soundness and wellbeing, he may be enabled to labour, and to acquire and preserve property, for the aid of those who are in want, that thus the stronger member may serve the weaker member, and we may be children of God, and busy for one another, bearing one another's burdens, and so fulfiling the law of Christ.
Martin Luther