First you’d have to show that it is a logical contradiction for a good God to permit evil in the world.
Kind of like a circle with corners.
If you can show that it’s impossible for a good God to permit evil, then you would have made your point.
However, since you referenced a microcosm, and appealed to “extrapolation”, let me give another microcosm of my own and ask you to extrapolate.
Do you think a good gather allows his child to suffer pain?
I can think of a wonderful example that’s right in the context of our discussion here.
Vaccinations.
So if you can see how a good daddy would permit suffering, (sometimes even assisting the medical assistant in holding down his child!), then you ought to be able to extrapolate to this:
A daddy can be good even while inflicting pain upon his child.
And God can be good even while permitting pain upon his creation.
NB: Please don’t go to “How dare you say vaccinations are the same thing as a tsunami that kills thousands of people!”
No one is saying vaccinations are the same. No one says it causes the same amount of suffering as a tsunami.*
It is only posited as an example that you can…extrapolate…to see that Good Beings Can Be Good even while Bad Things Occur To Their Loved Ones.
*The difference in quality between the pain of a vaccination and the suffering of a tsunami is indeed colossal. But it is finite.
However, the difference between a human father and God the Father is…infinite.
So, if anything, the analogy of vaccination to tsunami isn’t inadequate enough.