Be watchful “in the sense of looking out for eschatological events, expected to happen shortly” (Barrett ).

Stand firm in your faith: the Greek could mean either (1) “stand firm in your acceptance of Christian teaching” (compare 11.2 “maintain the traditions”) or (2) “stand firm in your trust in God and Christ.” Revised Standard Version chooses (2) as An American Translation does. Most translations, including Good News Bible, choose (1), the meaning of which is implied in the literal words “in the faith.”

Be courageous: this verb is not used elsewhere in the New Testament but is common in the Greek Old Testament, almost always with other verbs meaning “be strong.” See, for example, Deut 31.6, 7, 23.

Strong refers to strength of faith rather than muscular strength. The two words courageous and strong reinforce the words stand firm earlier in the verse.

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 .