According to the Bible's New Testament, the apostles were the primary disciples of Jesus, the central figure in Christianity. During the life and ministry of Jesus in the first century AD, the apostles were his closest followers and became the primary teachers of the gospel message of Jesus. The word "disciple" is sometimes used interchangeably with "apostle" for instance the Gospel of John makes no distinction between the two terms. In modern usage, prominent missionaries are identified as apostles a practice which stems from the Latin equivalent of apostle, , the source of the English word "missionary".