How do we know that perseverance in faith is a true doctrine?

In 2 Timothy 1:12, Paul states, 'For I know whom I have believed and am persuaded that he is able to keep that which I've committed unto him against that day.' This underscores the doctrine of perseverance, as true faith is characterized by a deep assurance in God's faithfulness. The believer's confidence is not in their own ability to maintain faith but in God's sovereign power to preserve them. This aligns with the Reformed understanding of the perseverance of the saints, where eternal security is guaranteed by God's preserving grace.