That was an expression favored by leadership sage Stephen Covey to explain how distrust can only be repaired by behaving in trustworthy ways.
Whenever we violate a trust or confidence, words can’t fix the problem. Apologies and regrets sooth bad feelings, but do not offer guarantees. Promises give others solace, but not permanent peace of mind.
The only way to regain trust is to stack up a pile of trustworthy acts. Slowly, over time, as more trustworthy acts occur in succession without a misstep, others begin to believe again.
Earning the credits to be trusted again is hard work. Moving on quickly after a misdeed is much easier for the transgressor. They often fail to understand how difficult it is for others to confer their trust ever again.
Because the guilty party believes the mistake was an aberration and not a reflection of their character, they become impatient with others who don’t instantly believe the same thing. But taking the leap to trust again requires proof. And the only proof is to behave in trustworthy ways until the memory of the transgression fades away.
Some relationship problems can only be resolved by behavior. You can’t talk your way out of them. Trust is built through consistency. When trust dies, it can only be resurrected through the long process of repeating trustworthy behaviors. The key word in “unwavering trust” is unwavering.
I like the word "unwavering" here as it describes just about the best humans can get in accurately describing how humans engage with trust.
It's on a spectrum that can probably reach Zero but not ever all the way to 100.