To what extent is the Pauline letter a distinctive form of Christian persuasion? It is in the area of inventio that we discover most clearly the distinctiveness of Paul's preaching. Although Paul appeals to some of the common proofs of rhetoric, many of these similarities of argument are more apparent than real, for Paul's relationship to his churches is central to his argumentation. Despite the apparent parallels to Paul's mode of discourse in ancient letter writing and oratory, there is something very different about his letters.1 This distinctiveness may be seen, in the first place, in the relationship of the speaker to his listeners. In most of his letters, Paul identifies himself as an apostle, signifying his authority and indicating the nature of his persuasion.

Even in those letters where he does not make apostolic claims (Phil., 1 and 2 Thess., Philemon), he speaks in the authoritative tones of a father admonishing his children (1 Thess. 2:11-12). His "appeals" (parakalo 1 Thess. 4:1; 5:14; Philemon 9) and "requests" (epotomen 1 Thess. 4:1; 5:12) to the community are only polite substitutes for the commands that would be appropriate (cf. Philemon 8). His use of the imperative in all of the letters also reflects his authoritative role among the churches. This tone of authority distinguishes Paul's persuasion, for he writes as a father who chooses to request compliance with his wishes rather than demand obedience from his children (Philemon 8-9).

In 1 and 2 Corinthians we gain special insight into the distinctiveness of Paul's communication. In both epistles he specifically identifies himself as "an apostle of Christ Jesus by the will of God" (1 Cor. 1:1; 2 Cor. 1:1), and he regards himself as a father to his churches (1 Cor. 4:14-21; 2 Cor. 12:14-15). This relationship is central to his persuasion, for the dominant aspect of his persuasion is the note of authority that accompanies his role as apostle and father to his churches. Paul's apostolic role is clearly indicated in the beginning section of 1 Corinthians. His thesis statement is "I appeal to you ... by the name of our Lord Jesus Christ" (1:10). That is, he speaks on behalf of Christ.

His persuasion rests not on "plausible words of wisdom," that is, oratorical proofs, but on the "demonstration of the Spirit and of power" (1 Cor. 2:4). In 1 Corinthians 2:6-16 Paul claims a privileged position that is rooted in "God's wisdom, secret and hidden" (2:7), but that is now known among the "mature" (2:6). Paul's gospel is not subject to normal rules of persuasion, for "God has revealed [it] to us through the Spirit" (2:10). Here, as George Kennedy has said, Paul appears to challenge the entire tradition of Greco-Roman rhetoric.2 Matthew and Paul "make extensive use of the forms of logical argument, but the validity of their arguments is entirely dependent on their assumptions, which cannot be logically and objectively proved."3

His arguments can be evaluated only by those who have the Spirit of God. Where his hearers evaluate preachers according to their own criteria, Paul declares that he is nothing more than a diakonos (3:5) through whom they believed. He and Apollos are nothing other than uperetai kai oikonomoi ("servants and stewards") of the mysteries of Christ (1 Cor. 4:1). Such mysteries are not subject to rational proofs because they are the revelation from God.