To the ancient Hebrews, angels were "bene Elohim" - God's sons, and very much a part of their everyday lives. So it is not surprising to find the Lord promising the people He loved the protection of His angels from the very beginning of His covenant with them. They might have been homeless pilgrims but in the culture shaped for them in God's covenant, angels existed without question.
In today's readings are several reminders of the role of angels: they are continually worshipping God (Matthew); they act as messengers and heralds from God (Exodus); and they act as our guardians (Ps. 90). Angels in these roles are not confined to the Biblical past. The Church has at various times dealt with the question of angels. St Thomas Aquinas devotes a whole chapter to angels in his 'Summa Theologica' (Part I).
Today, many books are written about actual angel-experiences. With superstition and the occult practices gaining ascendancy in the world, we need these reminders of a loving, concerned God, who said His angels to open our eyes to Him here in our midst, comforting and ministering to us in our need. God's angels remind us of the multitudes on the side of good, fighting sin and evil.
Thank You, Lord, for lovingly guarding us with Your angels so we can enjoy eternal life with You.