Miracles are supernatural acts of God's power that bear witness to His presence and message. The exodus plagues (Ex 7-12), the Red Sea, the manna, Elijah and Elisha's ministries, Christ's healings and exorcisms and resurrection, the apostolic signs of Acts. Three biblical purposes: confirmation of God's messengers, demonstration of God's power, and merciful relief of suffering. Many other signs truly did Jesus... but these are written, that ye might believe (Jn 20:30-31).
Supernatural acts of God's power; confirm His messengers, demonstrate His power, relieve suffering.
John's Gospel calls Christ's miracles signs (sēmeia, 17 times). Hebrews 2:4 names them signs and wonders, and divers miracles, and gifts of the Holy Ghost. Acts 2:22 (Peter at Pentecost): Jesus approved of God among you by miracles and wonders and signs.
John 20:30 — "And many other signs truly did Jesus in the presence of his disciples, which are not written in this book."
John 20:31 — "But these are written, that ye might believe that Jesus is the Christ, the Son of God."
Hebrews 2:4 — "God also bearing them witness, both with signs and wonders, and with divers miracles."
Modern naturalism rules out miracles a priori; Scripture and the apostolic witness assume them as real, witnessed, and evidential.
Whether miracles continue today (cessationism vs continuationism) is debated; that they happened in Scripture is not. Christ's resurrection is the great miracle on which Christianity stands or falls (1 Cor 15:14).
Greek sēmeia (signs), dynameis (mighty works), terata (wonders).
Greek sēmeion — sign; John's preferred term.
Greek dynamis — mighty work, miracle; same root as English dynamic.
"Confirmation, demonstration, relief."
"Christ's resurrection is the great miracle."
"Signs, wonders, and mighty works."