But grow in grace, and in the knowledge of our Lord and Saviour Jesus Grow - not only do not "fall from" (2 Peter 3:17), but grow onward: the secret of not going backward (Ephesians 4:15).
(The) grace, and ... knowledge of ... Christ - the grace of which Christ is the author; the knowledge of which Christ is the object.
Forever, х eis (G1519) heemeran (G2250) aioonos (G165)] - 'to the day of eternity:' the day that has no end; "the day of the Lord," beginning with the Lord's coming.