This view makes faith purely intellectual and does seem a little arbitrary. But if we have a complete view of faith, it no longer seems odd. It should not be thought that repentance and faith are a dual prerequisite for salvation. True faith entails true repentance. Therefore it always results in good works.
Every good tree bears good fruit, but a bad tree bears bad fruit.
A good tree cannot bear bad fruit, and a bad tree cannot bear good fruit. James 2.17 Faith by itself, if it is not accompanied by action, is dead. But this is a slightly more complex question. There is a common view that says that all that is necessary to be saved is to make Jesus one's Savior and not necessarily one's Lord . On this view, the repentance necessary for salvation is only intellectual.