Why is confident preaching important for Christians?

In 2 Corinthians 1:19-20, Paul asserts that his preaching is not ambiguous, but rather asserts that all the promises of God in Christ are 'yes' and 'amen.' This confidence allows believers to rest assured in their salvation and the assurances given by God. If a preacher were to present an uncertain message about God's power and faithfulness, it would lead to confusion and undermines the very essence of faith. Genuine preaching reflects the absolute truth of God’s Word and affirms the assurance that every chosen person will ultimately receive salvation, which glorifies God’s sovereignty and His unwavering promises.