From the Word
11 Beloved, I beseech you as aliens and exiles to abstain from the passions of the flesh that wage war against your soul. 12 Maintain good conduct among the Gentiles, so that in case they speak against you as wrongdoers, they may see your good deeds and glorify God on the day of visitation.
1 Peter 2:11–12, RSV
Peter admonishes Christians to Christlike lives and works in view of the fact that they are called to great glory, having become through Christ a royal priesthood, a people of God and citizens of heaven. He would have them occupy this temporal world as guests, striving after another and eternal kingdom; that is, to abstain from all carnal lusts and maintain a blameless walk, a life of good works. The apostle assigns two reasons for such self-denial: first, that we may not, through carnal, lustful habits, lose the spiritual and eternal; second, that God’s name and the glory we have in Christ may not be slandered among our heathen adversaries, but rather, because of our good works, be honored.
When Peter admonishes to “abstain from fleshly lusts, which war against the soul,” he implies that if we do not resist carnal inclinations, we shall lose our priceless eternal inheritance. To be a stranger on earth, striving after another and better life, is inconsistent with living in fleshly lusts as if one’s sole intent were to remain in the world forever. If you would have the things of one life, Peter says, you must forsake the things of the other. If you forget your fatherland and lie drunken in this carnal life, as does the heathen world in living in unbelief and without hope of eternal life, you will never reach yonder existence. It is necessary to strive if we are to withstand the lusts of the flesh; for these war against the soul—against faith and the good conscience of man. If lust triumphs, our hold on the Spirit and on faith is lost. If you would not be defeated, you must valiantly contend against carnal inclinations and maintain your spiritual, eternal good. Our own welfare demands the conquest.
But God’s honor also calls for it. God’s honor is affected by our manner of life here on earth. We are to avoid giving occasion for our enemies to open their mouths in calumniation of God’s name and his Word. Rather must we magnify the name of God by our confession and general conduct, and thus win others, who shall with us confess and honor him. “Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven.”
Luther, Martin, and John Sander. Devotional Readings from Luther’s Works for Every Day of the Year. Augustana Book Concern, 1915, pp. 213–14.