Peter, John, and Matthew were in the original apostolic company; they were with Jesus during his ministry for three and one-half years. They were by his side virtually day by day, hence they wrote as eyewitnesses of the things they saw and heard.
James (not the brother of John; cf. Acts 12:2) was a leader in the Jerusalem church (Acts 15:13; cf. Galatians 2:9), and a half-brother of Jesus…