I am debtor both to the Greeks and to the barbarians; both to the wise and to the unwise ... For I am not ashamed of the gospel of Christ: for it is the power of God unto salvation to everyone who believeth ... For therein is the righteousness of God revealed from faith to faith ... The just shall live by faith (Romans 1:14, 16, 17).
Debtor. It's a word that implies obligation, responsibility. Paul felt that because of what Christ had done in his life, he owed the nonbelievers a debt: the debt of bearing the gospel of Christ to them. The apostle's word also suggest a deep sense of commitment. Paul realized that men and women are made right with God to be an instrument through which the nonbeliever could acquire faith and, consequently, salvation. Realizing the crucial role of faith in salvation, he felt a deep commitment to the call.
As Christians, as bearers of the good news, we ought to be moved by the same sense of commitment and responsibility. We ought to feel obligated as a body to make visible to the world the love of God. We ought to discharge that obligation with commitment: in word, in deeds, and in our general behavior -- all three of them in harmony, not one of them as opposed to another one, and not doing one today and the other one tomorrow. We ought to practice responsible Christianity.