I must say that some of the symbols in this series are a little hard to make for tree-hanging purposes - but this is Harry's attempt at a doorway with blood - another day you'll get to see my attempt at Bethlehem (!?).
The readings are: Exodos 12:3, 5a, 6b-8, 11-13; John 1:29; 6:4, 52-54; 1 Corinthians 5:7b.
In the new Testament readings we find that Jesus is equated with this sacrificial lamb. The one whose blood was used to cause death to pass them over. And that is what Jesus was for us wasn't he? His blood was spilt so we might have eternal life.