It is significant that Jesus did not invite the disciples to tea, but rather said ‘Follow me’. Augustine found the idea of an effectual call in other biblical examples. So, Jesus commands, ‘Lazarus, come out’ (Jn.11:43), a speech act that literally wakes the dead. For Augustine, something similar happens each time God summons a person to new life.
(p. 343, Kevin Vanhoozer, "Effectual Call or Causal Effect? Summons, Sovereignty and Supervenient Grace", Tyndale Bulletin 49.2 (1998): 213-251)