How can we be sure that preaching is effective in bringing about faith?

The effectiveness of preaching in bringing about faith is rooted in the biblical assertion that faith comes by hearing the Word of God (Romans 10:17). Preachers are called to proclaim the gospel, delivering the message of Christ's redemptive work. Despite the weaknesses of the vessel, as Paul explained in 2 Corinthians 4:7, the power of the message comes from God, not from the preachers themselves. When the message is faithfully preached, the Holy Spirit works in the hearts of listeners, leading them to faith and understanding. Thus, the proper preaching of the gospel is both a means of grace and a source of spiritual nourishment for believers.