It can be helpful to sort out these three titles: (1) Disciples, (2) The Twelve, (3) Apostles
Disciple: This is from a Greek word that means “one who is taught, a learner, the follower of a master.” In the Gospels the word designates those specifically called by Jesus to follow him, and who actually traveled with him. Some of them were women. It is not known how many disciples there were. Luke, in his Gospel, speaks of Jesus sending 70+ disciples to preach, but it is assumed that there were more than this.
The Twelve: From among the "disciples" Jesus chose a distinct group to become "the Twelve: -- symbolizing the 12 tribes of Israel in the new covenant. Their names are listed in three of the Gospels and in the Acts of the Apostles, although there are some variations in the lists.
Apostle: This is from a Greek word that means “to send officially” as, for example, an ambassador. The term applies to “The Twelve,” but goes beyond them – apparently designating those specially “sent.” Paul, for example, calls himself an apostle. In his letter to the Romans, he also refers to a woman as an apostle: “Greet Andronicus and Junia…they are prominent among the apostles.” (John, in his Gospel, never uses “Apostle.”
Luke, in the Acts of the Apostles, is the first to extend the term “disciple” to refer to people who became Christians after Christ’s death and resurrection.
The Sea of Galilee is about 12 miles long and 7 miles wide and generally quite deep. Sudden changes of weather can create strong winds, and the gorges between the high hills surrounding the area can tunnel the winds onto the sea and create dangerous conditions, especially at night.
Some would say that Mark and Matthew include this story in their Gospels because they see it as a reassuring lesson for Christians after the resurrection and ascension. The boat represents the Church. The darkness and wind represent evils that threaten it. Jesus, who seems to be absent, comes to them and calms the wind and the waves.
In John’s account, the whole point of the story is simply the unexpected presence of the Lord – there is no “miracle” other than that (no calming of the wind and the waves). His presence is enough.
As individual Christians, and as a Church, we face crises from time to time. Some come from within, and some come from the outside. Both can bring fear and panic.
We need to hear the reassuring words of Jesus: “It is I. Do not be afraid.” Let him speak those words to you now.