Sigh.
You clearly haven’t been around any 2 year olds.
But, for the sake of argument, let’s use a 5 year old here.
You can explain the reasons why you are allowing your 5 year old to be stabbed painfully 4 times in his thigh, and, I guarantee you, he’s NEVER going to say, “Ok, Daddy. I get it! The principles of acquired immunity vs passive immunity, through the introduction of biochemical agents, which will stimulate my T-helper cells and B-cells to produce antibodies and memory cells is absolutely necessary! Bring on those shots!”
It is relevant to make a distinction between what is “hurtful” and what is “harmful.” A doctor giving a vaccine to a child is inflicting hurt, but is not harming the child; to the contrary, the child is being “treated” (helped) with a vaccination.
A doctor punching one’s child in the face, on the other hand…
As I see it, a good rule of thumb for the conduct of
human beings towards human beings is that the inflicting of hurt is allowable, if it has that person’s explicit or tacit consent and if it can be reasonably demonstrated to be a source of help. A vaccination or a surgery pass that test, albeit not in a foolproof manner (the surgery can go awry; the vacination can have side effects). But, all things being equal, subjecting the patient to that short-term “hurt” will likely prevent long-term hurt – and, even, prevent lasting harm.
As mentioned, there is also patient consent that is implicit, in the infliction of “hurt” by a doctor (I’ve also heard the analogy of how you wouldn’t let a stranger anywhere near your neck with a razor blade – unless he happened to be a barber). If you are an adult, you trust that the doctor knows what he is doing (if not, there’s always a malpractice lawsuit). You consent to the doctor’s “hurting” you (unless it is an emergency, where there is no time to consult you). If you are a child, it’s your parents that are giving consent to your being “hurt” by the doctor. They trust that the doctor knows what he is doing.
It’s also my view that – though this “hurt” versus “harm” distinction
may exist with God – that, if so, it may indeed defy comprehension. Therefore, I think, it is ultimately speculation on our part, and we should not try to figure it out on our own (if we try to hard too figure it out, we are in danger of “aping” the logic whereby we inflict pain on
each other, but with a confused understanding).
I think Christians generally “get” this – if they see suffering (hunger, disease) they seek to alleviate that suffering. They presume that this suffering is a great evil,
so long as there is something that can be done about it. When there is nothing that can done about it, then they consider that – perhaps – it is God’s will. But it’s ultimately a mystery – they can’t know for sure, and they certainly do not anticipate that suffering that
can be alleviated by humans is God’s will (e.g., let me leave that Samaritan bleeding in the ditch; perhaps it was
God that put him there, and for a good reason).
An alternative to suffering being God’s will is that such suffering was
not God’s will, but that you will be comforted on its account, in the afterlife.
For example, someone murders a child. That murder of the child may not have been God’s will; to the contrary, it was a product of the sin of the murderer. God never “wanted” it to happen, which is precisely why it was a sin on the part of the human being who committed it. But all will be made good, on the other side…