For we are become partakers (or, partners) of Christ, if only we hold fast the beginning of our confidence firm unto the end. This is a repetition in another form of the assertion of our position as Christians, with the appended condition, in Hebrews 3:6.
It is a question whether μέτοχοι χριστοῦ means that we partake of Christ as being in communion with him, or that we are partakers with him of the glory he has won for us (cf. συγκληρονόμοι χριστοῦ, Romans 8:17).
The first is undoubtedly the ordinary sense of μέτοχος with a genitive in classical Greek, and generally in the New Testament (cf. e.g. infra, Hebrews 6:4, ΄ετόχους πνεύματος ἁγίου), and is on this ground maintained by Bleek, Alford, and others; but in the LXX.
μέτοχος, followed by a genitive, is as undoubtedly used for" partner" or "companion;" of. Psalms 119:63, ΄έτοχος ἐγὼ εἰμι πάντων τῶν φοβουμένων σε: Hosea 4:17, ΄έτοχος εἰδώλων: and especially Psalms 45:7, ΄έτοχους σου, which has been already cited (Hebrews 1:9), and justifies, as it may prove suggested, the expression in this sense here.
Cf. also in the New Testament, Luke 5:7, where μετόχος, though without an expressed genitive following, occurs in the sense of "partner." Further, the second sense accords better than the first with the view of our relation to Christ so far set forth in the Epistle.