For: the transition word so rendered in Revised Standard Version is often translated “Because” (as in Anchor Bible). Here it introduces the basis for the content of the previous verse. It is because God made his light to shine in the hearts of Paul and his associates that they do not preach about themselves but about Jesus Christ.

Let light shine out of darkness is a freely-worded quotation of Gen 1.3. Translators may wish to indicate that Paul is quoting the Hebrew scriptures. Contemporary English Version makes this clear: “The Scriptures say, ‘God commanded light to shine in the dark.’ ” Note also that it will be better in some cases to follow the Contemporary English Version model in making this a separate sentence and starting anew with God as subject in the next part of the verse.

Who has shone: the subject of this clause is God. If this verse is divided into two sentences as suggested above, one may begin the second sentence here with “It is this same God who….”

In our hearts: for the translation of hearts see comments at 1.22 as well as the use of the term in 3.15. The pronoun our may refer to Paul and his associates only, or to all Christians in contrast to unbelievers (verse 4). While the focus here is probably on Paul and those with him, the receptor language should not give the impression that the light of the gospel had not shone in the hearts of the Corinthian believers.

The light of the knowledge of the glory of God in the face of Christ: the use of several nouns linked by the word of is similar in form and content to the end of verse 4. The light comes from the knowledge, though it is possible to understand knowledge as in apposition to light, that is, “that illumination that consists in the knowledge” (so Barrett). The word for knowledge in this context refers to essentially the same thing as “gospel” (see 2 Cor. 4.4).

The glory of God is the content of the knowledge. So it may be better in many languages to say “knowledge about the glory of God.” The word for glory here is the same as in 1.20 and is also found six times in chapter 3 as well as in verse 4 above.

In the face of Christ is contrasted with Moses’ face in 3.7. As Good News Translation makes explicit, God’s glory is “shining” in the face of Christ.

The editors of the UBS Greek New Testament follow manuscripts that say “in the face of Jesus Christ” (so New Revised Standard Version and Revised English Bible); but since many good manuscripts omit the name “Jesus,” the editors place the name Jesus in brackets. Neither Revised Standard Version nor Good News Translation follows the reading of the UBS Greek New Testament here. The evidence is so evenly divided that translators may follow either Revised Standard Version or New Revised Standard Version. The meaning is the same regardless of whether the name “Jesus” is included or omitted.

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 .