by Richard D. Draper
With this short phrase, Paul describes the very nature of mortality as designed by God. The meaning of the Greek word translated “walk” also denotes comportment or behavior. That the verb is in the present tense suggests that the Apostle has the whole of the mortal experience in mind. The preposition “by” acts, in this case, as a marker of instrumentality or circumstance whereby something is made possible. Because it modifies the noun “faith,” it stresses that it is this virtue that makes walking in a godly way possible.
As with the English noun “faith,” the Greek word has a wide range of meanings ranging from active belief to absolute sureness. The degree of a person’s faith expresses itself in the amount of trust and adherence that a person gives to the idea, teaching, cause, or person that she or he is attracted to. This is what separates faith from mere belief. The latter demands no adherence, only acceptance or admission. The former demands action. But there are degrees of faithfulness. Little faith expresses itself in adherence only when it is convenient or of little cost. Great faith expresses itself in adherence not only when such is inconvenient but also when it demands sacrifice. The noun as used by Paul connotes the high degree of confidence the Saints should have in the reliability of Jesus. The word also carries the strong nuance of conformity to the strictures the Lord demands of his people. Faith in him is expressed in one’s love for him as manifest in obedience to his will (John 14:15; compare Deut. 30:20; Eccl. 12:13). This is the quintessence of faith.
The noun translated as “sight” denotes both the outward form of something (its “appearance”) and also the act of looking or seeing something (that is, “sight”). Though the latter is the usual translation of the word, that reading gives a false understanding of Paul’s point because it suggests that he saw faith and sight as two differing human faculties. The false impression is resolved when we understand that he has more than mere human faculties in mind. His reality consists of things which are both seen and unseen (2 Corinthians 4:18). Just as faith is “not a mere faculty or sense but includes the content and hope of the Gospel, so ‘appearance’ does not signify the act of seeing but the object and content of sight, namely, the outward and visible present world.” Paul’s point is that worldly appearance is not what defines the path the Christian should walk. Certainly, for him, it is not appearance that counts but serving the Lord no matter how such service might appear to the world or to the more worldly members of the Corinthians branches.
This material is adapted from Richard D. Draper and Michael Rhodes, Paul’s Second Epistle to the Corinthians (Provo, Utah: Brigham Young University, BYU Studies, forthcoming).
 Mark A. Seifrid, The Second Letter to the Corinthians (Grand Rapids: Wm. B. Eerdmans, 2014), 233.