The beginning of verse 3 justifies Paul’s threat in verse 2, explaining why he is willing to punish the offenders. While Revised Standard Version continues the rather complex sentence begun in the previous verse, it will probably be better to start a new sentence here, as in Good News Translation. The word since introduces the reason why Paul will be strict on his next visit.

You desire proof: the verb used here is the same as in 1 Cor 1.22 and 4.2. The meaning is somewhat stronger than desire. In this context it is more like “demand” (An American Translation and Anchor Bible).

In the phrase Christ is speaking in me, the words in me are better translated as “through me” (Good News Translation), since the point is that Christ is speaking to the Corinthians by means of Paul, his apostle, his ambassador. Another way of saying this in some languages may be “Christ is speaking by my mouth” or “Christ is causing me to speak.”

He is not weak: the reference is to Christ. Some will rephrase this more naturally as “he does not lack strength.” It should be noted that this verse (together with verses 4 and 9) constitutes the conclusion of the strength and weakness theme which started in 10.10. Translators should insure that as far as possible the same words are used throughout for these key terms.

The words in you (Revised Standard Version, New Revised Standard Version, New American Bible) are better translated as in Good News Translation, “among you” (so also New Jerusalem Bible, New International Version, Revised English Bible, and God’s New Covenant). The focus is not on the spiritual working of Christ within each individual’s life (“in you”) but rather on his working within the collective life of the Christian community (“among you”).

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 .