It is not the oath that makes us believe the man, but the man the oath.

A promise is worth exactly what the person making it is worth. Contracts, guarantees and assurances add no credibility of their own; they restate what you already know about whether this person does what they said. Which is why the loudest assurances often come from the people whose ordinary word was not enough. The record is the evidence and the oath is only the packaging.

When you are offered a strong guarantee, look past it to what they have done before. And on your own side, stop adding emphasis to your commitments. Say it once, plainly, and then be the kind of person whose single saying is sufficient.