How do we know Demas's faith was not genuine?

The nature of Demas's departure raises questions about the authenticity of his faith. Throughout scripture, genuine faith is marked by perseverance and a steadfast commitment to Christ, even amidst trials and allurements. Demas, once a companion of Paul, allowed his desires for the present world to overshadow his earlier profession of faith. His choice to forsake Paul and the gospel indicates that his faith may have been based on external factors rather than a deep-rooted, saving faith in Christ.