2 Peter 3:18

ἐν χάριτι καὶ γνώσει τοῦ Κυρίου, κ. τ. λ. The genitive is to be taken with both words. γνῶσις here means “spiritual instruction,” a knowledge that has its source in Christ Himself, as distinct from ἐπίγνωσις, which is personal communion with Christ (see note 2 Peter 1:5). γνῶσις is the privilege of the “friend” of Christ. Cf. John 7:17; John 15:15. αὐτῷ. Note that the doxology is addressed to Christ, and, therefore, κυρίου ἡμῶν. also refers to Him. εἰς ἡμέραν αἰῶνος : “in the day of eternity”. The meanings of εἰς and ἐν in later Greek are somewhat interchangable (cf. Moulton, Proleg. 234 f.). ἡμ. αἰῶνος is a very rare phrase not found elsewhere in N.T. It is found in Sir 18:10, where the phrase is ἐν ἡμέρᾳ αἰῶνος. The more usual expression is εἰς τοὺς αἰῶνας τῶν αἰώνων. “ εἰς τοὺς αἰῶνας becomes so immediately the ruling phrase that this Petrine doxology cannot have been written alter liturgical expressions had become in any degree stereotyped” (Bigg).