Sinning, a present tense in the Greek, is expressed as future in Good News Bible in order to remind readers that since verse 10 (“Suppose”) Paul has been tactfully discussing a hypothetical or imaginary case, not a real one.

Wounding their conscience when it is weak does not mean that there are some times when a person’s conscience is weak, and other times when the same person’s conscience may be strong. Good News Bible‘s more literal translation, “wounding their weak conscience,” is closer to the meaning of the Greek. In some languages it may not be natural to speak of wounding someone’s conscience, and a more general expression may be better, such as “hurting their weak conscience,” “doing harm to their weak conscience,” “weakening their ability to decide between right and wrong,” or even “causing their ability to decide between right and wrong to become weak.” For the meaning of the Greek word translated “conscience,” see comments on 1 Cor. 8.7.

In this verse, as in verse 11, a translator needs to find a way of emphasizing the words you sin against Christ. Good News Bible has lost this emphasis by rearranging the sentence to produce a more flowing English style. One may maintain this emphasis by restructuring the verse slightly as follows: “When you commit sin against your fellow Christians and damage their consciences like this, you actually sin against Christ.”

In this verse, in contrast to verse 11, you is plural, but there is no difference in meaning, since “brother” in verse 11 means “any fellow Christian.”

Quoted with permission from Ellingworth, Paul and Hatton, Howard A. A Handbook on Paul’s First Letter to the Corinthians, 2nd edition. (UBS Handbook Series). New York: UBS, 1985/1994. For this and other handbooks for translators see here .