God is goodness itself. Because he acts completely in line with his good nature, God does good to all his creatures, but especially he does good to his people, even using suffering to bring about their good. God also must make us good. He does so by teaching us his word. And to do that, he must first open our eyes to the reality that on our own, we are not good.
Jesus is not just one prophet among many. Jesus is The Great Prophet who can reveal God perfectly to us, because he is God and near to God.
God isn't looking for witnesses who are impressive, but he's looking for witnesses who will testify to the coming of Jesus with joy, worship, and faith.