The readings for Easter 2 are from Acts 5:12-20; Revelation 1:4-18; and John 20:19-31.
A reading from Acts replaces the Old Testament lesson for Easter season because Jesus HAS fulfilled the OT and now we watch the results of that in Acts. Jesus described Himself as living water, He rose from the dead, and now we watch the tide coming in/water rising through the apostles’ witness. The healing work of Jesus continues through the apostles to authenticate their witness, which is preserved with all integrity for us in the NT. The religious authorities continue to use physical force against the kingdom of Christ, but such force is useless against a rising tide of living water. An angel brings the apostles out and commands them to resume their witness!
The Revelation to St. John gives us a look at how high the rising tide of Easter has come by the end of the first century. Though John is in exile on the island of Patmos, the Word of the Lord continues to grow across Asia Minor and beyond (seven churches are named, but these are parabolic—illustrative of all the churches of the New Testament). The risen Lord Jesus continues to strengthen His witness through the apostles, this time by appearing to John in a form that conveys invincibility; Jesus has conquered death and every other foe universally and now works to conquer them in our lives and in our times.
John, the author of Revelation and this Gospel reports history and is a permanent witness to the Rock upon which our lives as believers and the Body of Christ are built. Wherever the Word of God is, there is Jesus in the midst. The Word and Spirit of God easily pass through every human obstacle (like locked doors) and through our fear to be with us and proclaim peace. “Peace” in OT and NT has to do with wide open spaces; note the contrast with being locked in a room. Think of wide open spaces also in terms of opportunities, strategies, ideas, and a whole range of emotions that inspire us to carry forward the witness of Christ in our own time(s) and place(s). The Lord has blessed us further by the absence of Thomas that first Easter evening. Thomas cannot and will not come to rest in honesty about dependence (faith/belief/trust) in Jesus until His resurrection is proven—and so it was. Thomas has hands on Jesus for us. Do read the beginning of 1 John 1 where John refers to the various ways that Jesus demonstrated His resurrection and His will to bring life to all. Look at 1 Corinthians 15 for even more witnesses to the risen Jesus.