Apostle. The defection of Judas from the Twelve created a vacancy (unlike a death) and in order to maintain the number twelve intact, corresponding to twelve tribes of Israel, a successor was chosen. Of two nominees, Matthias was elected, either by lot or, possibly, by votes cast by the existing apostles. The qualifications for office were that those nominated should have accompanied Jesus during his ministry and been a witness to the resurrection (Acts 1: 22).