admonish, warned, aware, have been a witness against

Definition:

The term "admonish" means to firmly warn or advise someone.

Usually "admonish" means to advise someone not to do something.
In the body of Christ, believers are taught to admonish each other to avoid sin and to live holy lives.
The word "admonish" could be translated as "encourage not to sin" or "urge someone to not sin."