Angels were created higher than man. They weren't created as people and then became higher than man. They were created higher and man was created "a little lower than the angels." (Psalm 8)Jesus IS the Angel of the Lord in the OT.
And if we are to become like him, then that leads to reason that we will be angels too.
Psalm 8:3-6
[3]When I consider thy heavens, the work of thy fingers, the moon and the stars, which thou hast ordained;
[4]What is man, that thou art mindful of him? and the son of man, that thou visitest him?
[5]For thou hast made him a little lower than the angels, and hast crowned him with glory and honour.
[6]Thou madest him to have dominion over the works of thy hands; thou hast put all things under his feet:
The fact that angels and humans are not the same is stated in the fact that we (as sons of God by faith) will one day judge angels.
1 Corinthians 6:3
[3]Know ye not that we shall judge angels? how much more things that pertain to this life?
How do you suppose that the sons of God came in unto (which indicated sexual union) the daughters of men and their offspring were physically described as being as tall as a cedar tree, and having 6 toes on each foot, and 6 fingers on each hand? How many unequally yoked marriages bring about giant offspring with extra digits??
Scripture says that the angels desire to look into salvation. They are not recipients of salvation.
1 Peter 1:12
[12]Unto whom it was revealed, that not unto themselves, but unto us they did minister the things, which are now reported unto you by them that have preached the gospel unto you with the Holy Ghost sent down from heaven; which things the angels desire to look into.
When the angels left their first estate, they left their spiritual habitation/body when was the FIRST estate. Put the puzzle pieces together.
*Angels in heaven were created by God, therefore, they are called "sons of God."
*Angels' first estate is their spiritual abode.
*Angels can appear in a form that looks human, but they are not human. (If they were human, they wouldn't have to leave their first estate in order to take wives and create offspring that are physically very different than humans.)
*Scripture states that the angels/sons of God were present and shouted for joy at the creation of the earth, before man was created.
*On the other hand, Job, a righteous man, was not present at the creation of the earth.
*Angels marvel at the plan of salvation. They desire to look into it, yet are not recipients of it.