As Jesus taught His disciples in the Upper Room on the night before His death, He addressed them in light of their collective position as “the foundation” (Eph. 2:20) for the forthcoming church.
The church age would begin on a specific “day” (John 14:20) which, we know, would occur on Pentecost Sunday. Once this age began, these men would bear the responsibility of leading a worldwide evangelistic and teaching ministry.