To summarize: What was the general function and purpose of angels?

The angels constitute God's familia amongst whom strife occasionally breaks out, disturbing the peace upon earth. A Rabbi, accordingly, used to add this petition to his daily prayers: "May it be Thy will, 0 Lord our God, to grant peace in the household above and the household below."[1] They form a celestial court, and God does nothing in this world without consulting them. The final decision, however, rests with Him alone; [2] God consulted them about the creation of man yet overruled their objections.[3]

The angelic host as a body is a force which makes for righteousness in the world, although there are wicked angels among that body. Consider two striking sayings such as these: "At the time that the Israelites first said 'We will do' and then 'We will hear' [4] sixty myriads of ministering angels came, one for each of the people, and bound two crowns upon him, one for 'We will do' and the other for 'We will hear.'" When, however, they sinned with the golden calf, a hundred and twenty myriads of destroying angels came and snatched the crowns away." [5]  (See also article on the Shabbat evening hymn, Shalom Aleikhem)


[1] BT Ber. 16b
[2] BT Sanh. 18a
[3] Genesis Rabbah 8:4
[4] Exodus 24:7
[5] BT Shab. 88a