If someone is untrustworthy, it is best not to depend on them for anything. Do not expect their word to have any substance. The assurance they give, is merely a false hope of delivery.
People are quick to say and slow to do. Their word could not bind a puddle. So, expecting anything to come of their protestations is a long ride to nowhere.
If someone says they have changed, expect them to change back. Such do not stray from their former habits. They will return to what they were all along.
Something that is real needs no fanfare. Those determined to convince lack evidence of their claims. So, they throw words about to distract and deceive.
When light shines, darkness flees. What a person does will tell you who they are. It is telling when showing is the preference for proving.