How do we know that preaching is a calling from God?

Preaching is confirmed as a calling from God through the examples set by biblical figures like John the Baptist and Jesus. In Matthew 11, Jesus refers to John as the greatest prophet, emphasizing that God's messengers are appointed to deliver His message to His people. This distinction is not merely a human appointment but a divine commission, underscoring the weighty responsibility of preaching. True messengers of God do not seek their glory but are instruments in God's hands to proclaim His truth. Additionally, the effectiveness of their ministry is not dependent on their own merits but on the power of God working through their humility and faithfulness.