Good News Translation omits the word For, which links verses 16 and 17. This word is important, however, in that it clearly links verse 17 to the question in the previous verse. The sense is that Paul is certainly not sufficient, since (for) he preaches the gospel in its purity and, unlike so many other preachers, he relies on God.

As in verses 14-16, the pronoun we probably does not include the readers.

Instead of the words like so many, some manuscripts have “like the others.” The editors of the UBS Greek New Testament consider this second reading “too offensive an expression for Paul to have used in the context.” Even so, some translations follow the reading “like the others” (Moffatt and An American Translation, which reads “like most men”); and New Revised Standard Version lists the reading “like the others” in the footnote.

Peddlers of God’s word: the meaning is apparently that many others were preaching for the sole motive of making a profit. Revised English Bible says “We are not adulterating the word of God for profit.” Paul does not appear to be claiming that others were falsifying the gospel, though that is possible if 4.2 refers to the same persons. God’s word does not refer to the Old Testament. As also in 4.2, the reference is to the message from God, especially the message about Christ.

But as men of sincerity: literally “but as from sincerity.” Since Paul’s associates included women as well as men, some translations avoid using the word men and use a word such as “persons” (New Revised Standard Version), or they restructure the wording (Good News Translation, Revised English Bible) in order to avoid suggesting that Paul was referring to men only.

In the sight of God we speak in Christ: these same words occur in 12.19. “To speak in the sight of God” appears to suggest that Paul is speaking openly and truthfully before God, who judges wrongdoing. “To speak in Christ” is to speak as one who lives in union with Christ (see comment in 1.21). A possible model for this expression may be “we speak as Christians in the very presence of God.” One translation restructures the whole verse as follows: “We are not like many people who add other business to the affairs [or, business] of God. But we speak the whole truth in the eyes of God, because we are people of Christ, and it is God who has sent us.”

Some languages will require that this whole verse be restructured by saying something like the following:
• Many people treat the message from God as if it were a second-rate product for sale. But we are not like that. Rather we speak with sincerity in God’s presence because he sent us as servants of Christ.

Or similarly:
• A lot of people try to get rich from preaching God’s message. But we are God’s sincere messengers, and by the power of Christ we speak our message with God as our witness. (Contemporary English Version)

Quoted with permission from Omanson, Roger L. and Ellingworth, Paul. A Handbook on Paul’s Second Letter to the Corinthians. (UBS Handbook Series). New York: UBS, 1993. For this and other handbooks for translators see here .