In the months before his execution by the Nazis, Dietrich Bonhoeffer wrote: "I fear that Christians who stand with only one leg upon earth, also stand with only one leg in heaven." His concern was for Christians who had disengaged themselves from the world, who could stand by and watch atrocities committed as if the Christian message or individual Christian responsibility had no bearing whatsoever upon earthly affairs.
The fact of the matter is that the Christian faith intends full engagement in the world. Certainly the origin of this new life is otherworldly. Certainly Christian values are not those of the world. Certainly Christian hope takes us beyond this world. But it is in this world that God has called Christians to live, and it is this world's inhabitants that Christians must reach with the gospel. Engagement of this kind requires Christian credibility and participation in the life of the world.
Credibility especially depends on living, as far as possible, in a manner that the world considers to be respectable. "Respectability" was an important concept in Paul's day. But the values connected with it have always been subject to change. Therefore, the Christian life is first and always to be a clear expression of the will of God.
The church's respectability in the world was very much in Paul's mind as he addressed the various groups in the Cretan churches. This is evident from the patterns of behavior he encourages in 2:1-10, patterns that would have pleased any upright person in that day. It is equally evident in his affirmation of the social categories by which orderly community or civil life was defined. In verses 2-10 he divides the church according to customary social categories (generations, sexes, slaves), and he employs the household-code form of teaching to emphasize that Christians must practice a renewed or reformed quality of behavior within those categories (see commentary at 1 Tim 2:1).
This type of teaching encouraged participation in the social structure rather than withdrawal from it. Exemplary (Christian) behavior within the traditional relationships would help maintain or increase the church's credibility in the eyes of the world and promote the evangelistic mission. But Paul does not simply adopt secular rules of behavior. Whatever affinities this lifestyle might have with secular moral ideals, only faith in Christ can produce the Christian, reformed version (vv. 11-15). This is what Paul means by godly living; and godly living is what this passage is about.