That is, that I may be comforted together with you by the mutual faith both of you and me.
that is, that you and I may be mutually encouraged by each other's faith.
τοῦτο δέ ἐστιν, συμπαρακληθῆναι ἐν ὑμῖν διὰ τῆς ἐν ἀλλήλοις πίστεως ὑμῶν τε καὶ ἐμοῦ.
toyto de estin, symparaklēthēnai en ymin dia tēs en allēlois pisteōs ymōn te kai emoy.