This study offers a new look at Luke's writings in proposing Acts 2:33 as the interpretative key. It shows how the important passages of Luke-Acts (annunciation, baptism, ascension, Pentecost, etc.) find their meaning from the proclamation contained in Acts 2:33. It shows that Luke had to have had this proclamation in mind at the moment he structured the plan of this double volume. The study also contributes to the emphasis of the inseparability of the pneumatological challenges and the christological and ecclesiological ones in Luke's writings. It brings out in an incontestable manner, the great theological unity of the contents of the third Gospel and the book of Acts.