I disagree with your interpretations of the scriptures here. In Luke, Christ is giving a parable to the people, and at the beginning of vs 18, it states how he tells them to not grow weary or faint (restating Isaiah 40:31) I don't believe he is saying people are eagles, infact in other versions other than the KJV it says "vultures", not eagles-- here I think he is meaning that the people who are left will be left to die (hence scavenged on)
In Revelation, again I believe that God is not calling us, but fowl (or Birds) that he is inviting to literally scavenge on the flesh of the great people of earth (who think they are are so great).
I do believe that the saints will gather with Christ in the final battle-- I just do not believe we are referred to as "eagles", in these two scriptures, anyway. I believe in Isaiah it is a similie (a comparison using like or as, not literal).