One of those requirements is holding a certificate. The FAA guarantees that you meet that requirement by giving you one. That is why one of the definitions of "to certify" is "to give a certificate to".
To certify something is not to guarantee that it does not and never will have faults. You are making that part up.
Sigh, let me try this again.
The
Definition of Certify has four potential means, three of which do not completely apply:
Definition of certify
certified; certifying
transitive verb
1 : to attest authoritatively: such as
a : confirm
b : to present in formal communication
c : to attest as being true or as represented or as meeting a standard
d : to attest officially to the insanity of
2 : to inform with certainty : assure
3 : to guarantee (a personal check) as to signature and amount by so indicating on the face
4 : to recognize as having met special qualifications (as of a governmental agency or professional board) within a field agencies that certify teachers
The word "
Certificate", as a verb, has one definition, which is a synonym of the fourth definition of Certify:
Definition of certificate
certificated; certificating
transitive verb
: to testify to or authorize by a certificate; especially : certify 4
In order to remove any ambiguity, the folks who write the regulations opted to use the word "Certificate" instead of "Certify" to make it clear that in the context of when someone is certificated, they are not assuring or guaranteeing the abilities of the airman, but instead establishing that the person has met special qualifications.