Jesus ends his New Testament ministry with his forty-day post-resurrection appearances and gospel proclamation (kerygma). Very little is said in the New Testament about that special forty-day proclamation. In fact, most scholars believe that Luke closes his Gospel with that forty-day event, and opens his book of Acts of the Apostles with that same event.
Acts 1:3 matter-of-factly states that Jesus “shewed himself alive” to his Apostles “after his passion by many infallible proofs, being seen of them forty days [hēmerōn tesserakonta], and speaking of the things pertaining to the kingdom of God.” After a few more words about the immediate future, he ascended to heaven. The parallel texts in Luke 24 add more detail:
In Luke 24:15-32, on the road to Emmaus, Jesus preached forcefully to the Apostles, opening up to them “the scriptures,” “and beginning at Moses and all the prophets, he expounded unto them in all the scriptures the things concerning himself,” which included the entire Bible (24:44-45). In Luke 24:49, Jesus stated that the Apostles were to be “invested” or “clothed with power from on high” in Jerusalem. Finally, in Bethany, he blessed them and ascended into heaven (24:50-51), and from thence they returned to Jerusalem “and were continually in the temple, praising and blessing God” (24:53). All this takes place during the fifty-day count from the end of Passover until Pentecost.
Two things here should catch our primary attention: Acts 1:3 “things pertaining to the kingdom of God,” is, according to Johannes Munck, “a common expression for giving Christian instruction,” and Luke 24:49, “clothed [endusēsthe] with power from on high,” entails enduement or “endowment” of power. A third matter is briefly mentioned in 1 Peter 3:18, saying that Jesus “went and preached unto the spirits in prison,” and Jesus himself reassures John that “I have the keys of death and of Hades” (Rev 1:18), while the Apostles’ Creed likewise has him “descend into hell” (κατελθόντα εις τα κατώτατα). It is about such matters that this website concerns itself.
We provide an annotated bibliography of scholarly literature on the subject of that Forty-Day Ministry (evangelium quadraginta dierum), along with a complete listing of the primary early Christian sources, with summaries describing what they contain, and where the original text and translations can be found. We also list the esoteric topics or themes-in-common within that literature. Any suggestions will be greatly appreciated.
 Munck, Acts of the Apostles, Anchor Bible 31 (Doubleday, 1967), 5.