I have to disagree, there are places where they are 'support' but this is more of God using them to deliver messages or for comfort. But in other places (like w/ Balaam, and in Revelation) they are not assisting Humans at all. Some of the pastors that I have asked even question if when an Angel came to deliever a message if that could actually be 'helping' because they're goal there is to deliver a message to further God's plan, not to assist people.
I do kindof want to agree w/ that because everyone was lost at one time and the only way they decided to obey God was because something amazing happened that they witnessed. I think people forget that in the end 'rescuing a Lost Soul' is actually telling them the gospel and them accepting it, which according to the pastors I have talked too, seem to say is what Angels do too.