Times have changed. God has not. Immutability is one of His key attributes. “I the LORD do not change” (ref. Malachi 3:6). This and other theological truths matter immensely. We must get God right, or everything else will ultimately go wrong.
It’s been told, and fairly well observed, that the difference between dogs and cats is this: your dog thinks you are god, while your cat thinks it is god.
Isaiah was the pessimistic prophet with the messianic hope. His sermons were dark clouds of gloom and doom, but they contained a silver lining and a golden promise. One day, he prophesied, a child would change everything.