A.T. Robertson Commentary Ephesians 3:1

"For this cause I Paul, the prisoner of Christ Jesus in behalf of you Gentiles,--" — Ephesians 3:1 (ASV)

For this cause (τουτου χαριν). Use of χαριν (accusative of χαρις) as a preposition with the genitive and referring to the preceding argument about God's elective grace. It is possible that Paul started to make the prayer that comes in verses 14-21 when he repeats τουτου χαριν. If so, he is diverted by his own words "the prisoner of Christ Jesus in behalf of you Gentiles" (ο δεσμιος του Χριστου Ιησου υπερ υμων των εθνων) to set forth in a rich paragraph (1-13) God's use of him for the Gentiles.