"Grace, mercy and peace from God the Father and from Jesus Christ, the Father's Son, will be with us in truth and love." (II John 3)
Grace is God doing what we do not deserve. Mercy is God not doing to us what we DO deserve; Peace is God giving us what we need based upon his grace and mercy. Commentaries concur that the word order is significant. God's grace always precedes anything. Mercy and peace flow from His grace.
The end of this greeting closes with the words truth and love. BOTH are essential to a Christian, to his/her local congregation, and to evangelism around the world. The church has to show a commitment to a truth that is not compromised in any way and must love each other in a way that is limitless.
"Grace, mercy and peace flourish in an environment where truth and love prevail." (Akin, Commentary on I, II and III John) As we intentionally share the gospel, we must show in our actions and attitudes mercy and peace and emphasize God's grace in giving us what we do not deserve In addition, we must also hold strong to the truth of the gospel and not let anything contrary to God's Word ever take root in our heart or the church at large.