Hebrews 1:3-4 describes the dramatic transitional period in which God begot Christ, making Him the only human being who could qualify as our Messiah and Savior.
Angels were endowed with the capacity to think, reason, and form attitudes. Their function was and is to be God's messengers and ministers to His creation.
God created angels as ministering spirits to take care of the heirs of salvation. The Bible is filled with examples of angels rescuing God's people from harm.