Jacob sent actual angels to Esau! What was his purpose? Messengers would have sufficed. It was to indicate the greatness of peace. That is what the text of the Jerusalem Talmud means, in saying that angels are half fire and half water, and that He who makes peace in His heavens made the angels thus to show that it is best to be at peace. This is what he meant to indicate to Esau, that he be at peace with him…Jacob's most passionate wish was to make peace with Esau. The parable told by our Sages, of blessed memory, is well-known: With what shall I bless you? If with children – these you have; if with wealth – this you have. This explains the difficulty presented by what it says, asking which blessing Jacob required. For he had children, and wealth as well. What did he seek? Peace. This why the Birkat Cohanim says "…and grant you peace", that he might have it with his brother Esau, for that was his passionate wish.