That angels exist is clear from Scripture as well as Sacred Tradition. Angels are purely spiritual creatures, they do not have bodies, and are not constrained by bodies as we are. They are personal and immortal, just as we are. They have intellects and free will, just as we do. Because an angel's mind does not depend on a body, an angel cannot forget or get confused and his will is much stronger than ours.
Angels are different from humans.
Our souls will be in heaven with the angels until the last day when our bodies will be raised and join our souls again. The Bible is full of examples of God using the angels as protectors of His people, as guides and as messengers. The two angels who came to Sodom and Gomorrah, the Archangel Gabriel announcing God's will that His Son should become Man to the Virgin Mary, the Angels consoling Jesus in the Desert and in the Garden. Before He created Man, God created the Angels. He gave them intellect and free will also.