How do we know the doctrine of salvation by faith alone is true?

The doctrine of salvation by faith alone is grounded in the apostolic teachings and affirmed throughout the New Testament. For instance, Romans 3:28 states, 'For we hold that one is justified by faith apart from works of the law.' This clearly articulates that faith, rather than human effort or righteousness, is the sole means of justification. Furthermore, the believer's internal experience of faith and the transformative work of the Holy Spirit confirm this truth, as seen in Ephesians 2:8-9, where it is stated that salvation is a gift of God, not a result of works, ensuring that no one may boast.