How do we know if someone has true faith?

A genuine believer in Christ will display a transformed life, marked by love for others and a desire to live according to God's commandments. James challenges believers to show their faith through their actions, suggesting that true faith cannot exist in isolation from works. As stated in 1 John 3:3, 'Every man that hath this hope in him purifieth himself, even as he is pure.' This illustrates that the believer's actions are a reflection of their relationship with God and the faith given to them.