What's the difference between impenitence and impenitent?

Impenitence

Definition:

• (n.) The condition of being impenitent; failure or refusal to repent; hardness of heart.

Example Sentences:

Impenitent

Definition:

• (a.) Not penitent; not repenting of sin; not contrite; of a hard heart.
• (n.) One who is not penitent.

Example Sentences: