I can identify with the last paragraph, in the context of my own different religious tradition, with certain other difference as well.
Darwin found himself in the unhappy position of having his faith undermined by what he saw as the non-directed processes of geological and biological evolution.
The ideas of Ernst Haeckel, in his youth a hardline Darwinian materialist, were to evolve to a surprising degree.
If redwoods are a byword for great stature, grasshoppers represent the opposite. And what insect could be more common or familiar?
So he chose to call himself David, after the Old Testament king who slew Goliath.