Our world is not the only world . The Bible is silent, but suggests that there are other worlds out there. God has many messengers in the Universe . Angels go around the Universe taking God's messages and do wonderful things for Him. Angels are God's Ambassadors.
Angels can travel faster than light.
Angels do whatever God asks. Angels must not be worshipped, for they are created beings like humans. Angels appear in different forms. A major part of an angel's work is working for humans in this sinful world. Back in the beginning, all was love and harmony.