As I've written about before hereand here, one of the great contributions of the Lutheran wing of the Reformation to Christian theology was the emphasis on vocation and the normalcy of the "ordinary" Christian life. While Luther wrote on this quite a bit, the emphasis on the theology of vocation did not die within Lutheran circles. This excerpt comes from the pen of C.F.W. Walther, one of the founding fathers of the Lutheran Church - Missouri Synod. His take on vocation has a different emphasis from Luther's and focuses on the Christian living out his or her life and vocation as a testimony to our faith:
We see that Christians should justify their faith before the world, above all, by conscientiousness and faithfulness in their offices and callings. Unfortunately, many who show themselves as zealous Christians in pious exercises are slow, careless, and unfaithful in their callings. They think the essence of Christianity consists of diligent praying and reading and churchgoing, of refraining from the vanity of the world, of pious speech, and of the holy appearance of many works. When the world sees that those who boast of faith are indeed diligent in such seemingly holy exercises but are unfaithful in their work, as well as terrible spouses, parents, and workers, the world concludes that the faith of the Christians is an idle speculation, making people useless for this life. In addition, it views Christians as either poor beggars or hypocritical deceivers.
Therefore, whoever wants to be a Christian must justify his faith before the world by the manner in which he conducts himself in his vocation. The faith of a husband and father leads him to care for the temporal needs and the eternal salvation of his family, to love his wife as Christ loved the Church and to raise his children in the fear and admonition of the Lord. The faith of a wife and mother prompts her to be subject to her husband in all humility, standing at his side as a true helper, caring for her children with tenderness, and teaching them the first letters of saving knowledge. The faith of a businessman results in good work for his customers; if he works for himself, he does not enrich himself from the sweat of the poor, but rather regards his poor workers as better than himself. The faith of the servant or day laborer is revealed in work that is performed, not for the sake of mere wages or for display before the eyes of men, but to serve men as Jesus Christ Himself. The faith of those who work in churches, schools, and communities causes them to act out of love for their Savior rather than for financial or other worldly gain.
In all our pursuits, let us demonstrate that faith makes us the best we can be. In this way, we justify our faith before the world.