2. Grace and peace. By grace is designated God’s paternal favor towards us. We have indeed been once for all reconciled to God by the death of Christ, and by faith we come to the possession of this so great a benefit; but as we perceive the grace of God according to the measure of our faith, it is said to increase according to our perception when it becomes more fully known to us.
Peace is added; for as the beginning of our happiness is when God receives us into favor; so the more he confirms his love in our hearts, the richer blessing he confers on us, so that we become happy and prosperous in all things,
Through the knowledge, literally, in the knowledge; but the preposition ἐν often means “through” or “with:” yet both senses may suit the context. I am, however, more disposed to adopt the former. For the more any one advances in the knowledge of God, every kind of blessing increases also equally with the sense of divine love. Whosoever then aspires to the full fruition of the blessed life which is mentioned by Peter, must remember to observe the right way. He connects together at the same time the knowledge of God and of Christ; because God cannot be rightly known except in Christ, according to that saying,
“No one knoweth the Father but the Son, and he to whom the Son will reveal him.” (Matthew 11:27)