It would be quite convenient to know where the word prevenient comes from. Can you find two relatives of "prevenient" in that sentence? You probably guessed that "convenient" is a cousin - and you're right; it derives from the Latin verb convenire, meaning "to come together or "to be suitable," which is itself from venire, meaning "to come." "Prevenient," which first appeared in English in the 17th century, comes to us from the Latin praevenire ("to come before" or "to anticipate"), which is also from "venire." The other (albeit distant) relative of "prevenient" in the opening sentence is "come"; it shares an ancient ancestor with "venire."
Word History
Etymology
Latin praevenient-, praeveniens, present participle of praevenire