How do we know that Scripture is the only source of truth for salvation?

Philip's declaration to Nathanael in John 1:45 emphasizes that Jesus of Nazareth is the fulfillment of the law and the prophets. This profound truth highlights that Scripture is the only infallible guide for understanding how sinners can be saved through grace. In Hebrews 10:1-18, it's made clear that the sacrifices of the Old Testament can never fully atone for sin, but Christ’s sacrificial death does. Thus, as believers, we find our assurance of salvation solely in the promises and truths of Scripture, for God’s Word is entirely trustworthy and capable of guiding us to eternal life.