John Calvin Commentary 2 Peter 3:18

"But grow in the grace and knowledge of our Lord and Saviour Jesus Christ. To him [be] the glory both now and for ever. Amen." — 2 Peter 3:18 (ASV)

But grow in grace. He also exhorts us to make progress; for it is the only way of persevering, to make continual advances, and not to stand still in the middle of our journey; as though he had said that only those who labored to make progress daily would be safe.

The word grace, I take in a general sense, as meaning those spiritual gifts we obtain through Christ. But as we become partakers of these blessings according to the measure of our faith, knowledge is added to grace; as though he had said that as faith increases, so would follow the increase of grace.

To him be glory. This is a remarkable passage to prove the divinity of Christ; for what is said cannot belong to anyone but God alone. The adverb of the present time, now, is designed for this purpose, that we may not rob Christ of his glory, during our warfare in the world. He then adds, for ever, that we may now form some idea of his eternal kingdom, which will make known to us his full and perfect glory.