Zechariah was a prophet in Jerusalem after the exile who encouraged the people to rebuild the temple. He emphasized that God uses prophets to teach and correct His people, and that disobedience brings punishment, while obedience brings blessing. Zechariah's visions foretold a future messianic king and salvation available to all nations through God's mercy. The book conveys messages of hope, joy in God's redemption, and trusting God even in difficult times.