How do we know faith in Christ is truly saving faith?

Saving faith is not merely intellectual assent to the existence of Christ or acknowledgment of His deeds. It is a deep, personal trust in Christ's righteousness for salvation, as articulated in Galatians 2:16, where Paul emphasizes justification by faith in Christ. This faith results in a transformation of the believer's heart and life, producing the fruit of repentance and a desire to live according to God's will. 1 John 5:1 supports this by stating, 'Everyone who believes that Jesus is the Christ is born of God,' indicating that genuine faith is accompanied by a new birth, leading to a life changed by the Spirit.