Rain and Joseph’s brothers were mentioned; I might add the flood, Abraham’s promised child in old age, many of the plagues of Egypt, Pharaoh’s hardened heart, the feast of quail in the desert, various victories (and defeats) in Israel’s wars, David’s victory over Goliath, the drought in Israel during the days of Elijah, Rehoboam’s harsh policies.
But again, I’d advise asking him questions to ensure you truly understand the full and specific nature nature of his objection. I’ve further thought about your question, and am still inclined to doubt that his difficulty is as to whether God can or cannot “guide” or otherwise use or utilize natural processes to accomplish his purposes.
Most people I’ve discussed this with would not so object, this is not what they would mean by saying “God or Evolution”. Rather, it is simply that they think science has completely removed any need to believe in God. If blind, unguided natural processes can in fact explain every single phenomenon we find in this universe without exception, then they find no logically compelling reason to embrace belief in God rather than their atheistic belief. Belief in God becomes an appendage, something ancillary, something unnecessarily tacked-on. Everything we see in this universe is perfectly explicable by scientific means in the very same way that Dawkins and others suggest.
In other words, since science (at least in theory) can explain literally everything, then there is absolutely no evidence in this cosmos for the existence of God, no reason to posit his existence. Atheists thus view belief in God as a completely unnecessary belief entirely arbitrarily tacked on to a system that needs no further explanation. Kind of like Richard Dawkins’s quote:
“There may be fairies at the bottom of the garden. There is no evidence for it, but you can’t prove that there aren’t any, so shouldn’t we be agnostic with respect to fairies?” Similarly, I imagine your brother views it this way. There may hypothetically be a God… but the world, as it exists, would look exactly the same whether or not Theistic Evolution is actually correct, or whether Richard Dawkins is correct. If this is so, the God is extraneous to their system. I’m guessing, at least, this is your brother’s point.
I really imagine this is his core issue. If you can, I’d encourage you to ask your brother if that is his core issue… if you find out, it would probably help folks here (not to mention yourself) better focus the discussion to most profit here.