23 So they nominated two men: Joseph called Barsabbas (also known as Justus) and Matthias. 24 Then they prayed, “Lord, you know everyone’s heart. Show us which of these two you have chosen 25 to take over this apostolic ministry, which Judas left to go where he belongs.” 26 Then they cast lots, and the lot fell to Matthias; so he was added to the eleven apostles.
Two supremely important truths:
First, it tells us that the function of an apostle was to be a witness to the resurrection. The real mark of Christians is not that they know about Jesus but they know Jesus.
Second, it tells us that the qualification of an apostle was that the person must have been with Jesus. The real Christian is the one who lives day by day with Jesus.