Even within intrinsically good duties, the way an obligation ends is not identical in every case. Some requirements are classified as not admitting lapse, while others may end through performance or a legally recognized removal of the obligation.
Does not admit lapse: the underlying duty of faith is the stated illustration.
Admits lapse: a prescribed worship duty may be discharged by performing it or removed in a circumstance the law recognizes.
This is a distinction about the discharge or lapse of duty, not a denial that both acts have intrinsic goodness.