John's ministry became so popular that many people from Jerusalem and Judea came to hear him.
Confessing their sins: Those who listened to John's preaching and turned away from sin were ready to accept the ministry of Jesus (Luke 7:27, 29).
they were baptized: John's practice of baptism might have started with the Old Testament idea of purification (see Isaiah 1:16; 4:4; Ezekiel 36:25).