A.T. Robertson Commentary Acts 26:23

"how that the Christ must suffer, [and] how that he first by the resurrection of the dead should proclaim light both to the people and to the Gentiles." — Acts 26:23 (ASV)

How that the Christ must suffer (ε παθητος ο Χριστος). Literally, "if the Messiah is subject to suffering." Ε can here mean "whether" as in Heb 7:15. This use of a verbal in -τος for capability or possibility occurs in the N.T. alone in παθητος (Robertson, Grammar, p. 157). This word occurs in Plutarch in this sense. It is like the Latin patibilis and is from pascho. Here alone in N.T. Paul is speaking from the Jewish point of view. Most rabbis had not rightly understood Isa 53. When the Baptist called Jesus "the Lamb of God" (John 1:29) it was a startling idea. It is not then "must suffer" here, but "can suffer." The Cross of Christ was a stumbling-block to the rabbis.

How that he first by the resurrection of the dead (ε πρωτος εξ αναστασεως νεκρων). Same construction with ε (whether). This point Paul had often discussed with the Jews: "whether he (the Messiah) by a resurrection of dead people." Others had been raised from the dead, but Christ is the first (πρωτος) who arose from the dead and no longer dies (Romans 6:19) and proclaims light (φως μελλε καταγγελλειν). Paul is still speaking from the Jewish standpoint: "is about to (going to) proclaim light." See verse 18 for "light" and Lu 2:32.

Both to the people and to the Gentiles (τω τε λαω κα τοις εθνεσιν). See verse 17. It was at the word Gentiles (εθνη) that the mob lost control of themselves in the speech from the stairs (22:21f.). So it is here, only not because of that word, but because of the word "resurrection" (αναστασις).