The task of the apostles was to bear witness to Jesus’ life, death, resurrection, and ascension. Along with saying what happened to Jesus, they must also convey Jesus’ teaching about the kingdom (Acts 1:3). They were the once-for-all foundation upon which Jesus Christ built his church (Ephesians 2:20).1
22 beginning from the baptism of John until the day when he was taken up from us one of these men must become with us a witness to his resurrection.”