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 has communicated tirelessly with humanity through men and angels. The first chapters of Hebrews displays Christ's superiority over even the angels.