Grace summarizes God’s saving work through Christ Jesus (Romans 3:24; Romans 5:15; Ephesians 2:8; 2 Thessalonians 2:16) and embraces divine enablement so that his people may do his will (Acts 15:40; 2 Corinthians 8:1, 2 Corinthians 8:7; Galatians 2:9; 1 Peter 5:12). Peace could be an experience of peace that comes from knowing God1 or the peace that we have with God (Romans 5:1) which constitutes salvation. In the New Testament letters, a wish-prayer takes the place of a wish for health which was common in letters written at the time. This is one of the ways in which Christian believers adapted the customs of their age. By praying for grace and peace [to] be multiplied to you,
Peter is asking the Lord to help his people grow in their knowledge of what he has done so that they will grow in godliness.2
2 May grace and peace be multiplied to you in the knowledge of God and of Jesus our Lord.