What is the benefit of the morning and evening remembrances (adhkar) that are supposed to protect us, if a person is afflicted with harm despite his certainty in them?

Legitimate remembrances (dhikr) are a means of preserving the servant, but their effect may be hindered by the presence of an impediment or the absence of a condition, depending on the servant's own state. They are like a weapon in the hand of its bearer; its benefit is not realized except with a strong arm. The answer to supplication (du'a) has multiple forms: it may be by fulfilling the request, averting evil from him, or saving it for the Afterlife.