"In today's Gospel reading, Luke summarises the last commission of Jesus to His Apostles. He goes out of His way to emphasise the reality of His bodily resurrection by sharing the meal with them, thus demonstrating for us His continued presence in the Church's Eucharistic celebrations.

Jesus gives them a new understanding of the Old Testament to show them how it bears witness to Him, of His suffering and resurrection on the third day, and then of the proclamation of repentance and forgiveness of sins to all men and women. This was to be their mission: their preaching of Christ was to be similarly scriptural always.

In John's First Letter today, John teaches the same lesson of Christ as expiation for our sins. While advocating a life of commitment to the commandments, of living what one preached, John also recollects that Jesus's sacrifice "takes one's sins away" (v.2) and that He is our advocate with the Father. Forgiveness is God's love revealed in Jesus' sacrifice. The experience of such irrational and lavish love is the everlasting gift of the Risen Christ to His followers.

This same truth is what Peter addresses in his second speech to the Israelites. Accepting responsibility for their actions which led to the death of Jesus and repenting it all would wipe out their sins and make them a resurrected people too.