If healers never verify their healings with follow-up and all their subjects are strangers they never see again, they have no way of knowing whether the healings were real.

Mike argues that healing ministers who only heal strangers in public contexts and never follow up cannot know whether those healings persisted. He contrasts this with his own circle where he and his loved ones are never apparently healed through these methods. He implies that if the healer can't heal those close to them, the stranger healings may not be real either.