How do we know the truth of God's Word is powerful?

God's Word is described as living and powerful (Hebrews 4:12) and is the means of God's grace working in the hearts of sinners. In Acts 4:13-14, Peter and John's powerful preaching resulted in undeniable miracles that affirmed the truth of their message. Despite their lack of formal education, the apostles' confidence came from being with Jesus. The truth they preached had the authority of Scripture behind it, which does not depend on outward appearances or personal qualifications. Instead, it is the Spirit of God who applies the Word to the hearts of individuals, confirming its power and transforming lives. This demonstrates that the efficacy of God's Word lies in its divine origin, and it is effective for salvation for all who believe (Romans 1:16).