If X is the necessary condition of A, then it doesn't follow that X is sufficient. However, if X were a sufficient condition, would it also follow that X is a necessary condition? Put otherwise, is a sufficient condition simply a set of all necessary conditions that conjointly would guarantee that A obtains?
Being able to drive is necessary, but is not sufficient, for qualifying as a good driver.
Being able to drive well is both a necessary and sufficient condition to qualify as a good driver.