When he shall come to be glorified in his saints, and to be admired in all them that believe (because our testimony among you was believed) in that day.
on the day he comes to be glorified in his holy people and to be marveled at among all those who have believed. This includes you, because you believed our testimony to you.
ὅταν ἔλθῃ ἐνδοξασθῆναι ἐν τοῖς ἁγίοις αὐτοῦ, καὶ θαυμασθῆναι ἐν πᾶσιν τοῖς πιστεύσασιν ὅτι ἐπιστεύθη τὸ μαρτύριον ἡμῶν ἐφ' ὑμᾶς ἐν τῇ ἡμέρᾳ ἐκείνῃ.
otan elthē endoxasthēnai en tois agiois aytoy, kai thaymasthēnai en pasin tois pisteysasin oti episteythē to martyrion ēmōn eph' ymas en tē ēmera ekeinē.