Luke 1:26; “And in the sixth month the angel Gabriel was sent from God unto a city of Galilee, named Nazareth.”
Angels are mentioned at least 108 times in the OT and 165 times in the NT (Chafer, Systematic Theology, II, 3). Angels aren’t glorified human beings, nor do they have the ability to morph themselves into something else. They were created by God for a number of different functions in which they serve Him.
The Bible explicitly says they don’t marry or reproduce like humans do – Matthew 22:30 – and are here as ministering spirits – Hebrews 1:14. They can take on the appearance of humans – Hebrews 13:2 – and in fact most of the times humans have interacted with them they’ve appeared in human form.
A great article can be read at ChristianAnswers.net that gives one of the most detailed accounts of angels I’ve read in a long time.
Another great resource of reliable information is David Jeremiah’s book “What the Bible says about Angels”.
