This is one of my favorite Bauckham quotes, taken from God Crucified: Monotheism and Christology in the New Testament (p.72). If you’ve not read the book, you should. It’s a good read!
[T]the identity of the God of Israel does not exclude the unexpected and surprising. Quite the contrary, this God’s freedom as God requires his freedom from all human expectations, even those based on his revealed identity. He may act in new and surprising ways, in which he proves to be the same God, consistent with his known identity, but in unexpected ways. He is both free and faithful. He is not capricious nor is he predictable. He may be trusted to be consistent with himself, but he may surprise in the ways he proves consistent with his himself. The consistency can only be appreciated with hindsight.
See also Mike’s earlier post The Christian God is Surprising.