I'm not sure how this would be categorized, but getting the coin and burying it called upon Harry for significant actions. First, Harry raced to out-reach toddler Harry C to slap his hand down over the coin to protect the child. That's a knowing and intentional act of sacrifice, because Harry knew how incredibly dangerous it was to touch a coin without protective fabric between skin and coin. There was no time to take any precautions because little Harry C would have grasped the coin, so Harry D chose to take the hit instead.
Second, and related, is that Harry immediately and decisively sealed the coin away from himself and everyone else. No one in the Church, which is the only history we know, has known of any other person who has resisted the temptation. That leads into a third point, or at least an extension of the second point, in that Harry kept resisting the temptation. Lash ran the gamut - more personal power, less personal discomforts, and perhaps the most insidious one, that of how much good Harry could accomplish for others if only he had the assistance of partnering with Lasciel and her fellow denarians.
A less courageous man would have hesitated that split second which would have meant that little Harry C got to the shiny thing first. Harry may not have a conventional set of beliefs about TWG and the afterlife, but Harry did know how absolutely devastated the lives of human hosts had all become.
Grabbing a hot metal poker without knowing that hot metal burns one's flesh is one thing. The poker will sear and scorch but the mental choice to grasp it was simply uninformed, not brave.
OTOH, to know what the red-hot metal will do to you, how excruciating the pain will be, and still to do so because one needs to do it in order to protect an innocent -- that's selflessness and valor.
Harry not only resisted Lash all that time but even interacted with her enough that he persuaded her to "self-actualize", if one were to wrap it in psych lingo. Harry persuaded her to form an intent of her own and to break with her own origin and source. She chose a better purpose for her existence than the one she had begun with. Without Harry, Lash wouldn't have become an entity of her own.