Look at Paul's letters. They end with the very same affirmation. Grace is the faithfulness of God whereby God keeps his promise to be our God and not give up on us. Grace points to God's mercy-riddled steadfastness. Peace, shalom, is God's end-time restoration of the creation when everything which contradicts the love of God and the truth of God, everything which harasses God's people, will be dispelled forever.
Every epistle begins and ends with the pronouncement of grace and peace.
Highly disturbing stuff. In Corinth one parishioner was committing incest and appeared not to be the slightest bit upset about it. Some women in the congregation were dressing like streetwalkers and speaking out with comparable brazenness. Some charismatics were trying to turn the service of worship into an emotional exhibition. In Galatia some church-members were bent on circumcising everything in sight, thinking that in order to be a Christian you first had to become a Jew.