Are they not all ministering spirits, sent forth the minister for them who shall be heirs of salvation? Hebrews 1:14
The connection of the visible with the invisible world, the ministration of angels of God, and the agency of evil spirits,, are plainly revealed in the Scriptures, and inseparably interwoven with human history. There is a growing tendency to disbelief in the existence of evil spirits, while the holy angels that "minister for them who shall be heirs of salvation" (Hebrews 1:14) are regarded by many as spirits of the dead. But the Scriptures not only teach the existence of angels, both good and evil, but present unquestionable proof that these are not disembodied spirits of dead men.
Before the creation of man, angels were in existence; for when the foundations of the earth were laid, "the morning stars sang together, and all the sons of God shouted for joy" (Job 38:7). After the fall of man, angels were sent to guard the tree of life, and this before a human being had died. Angels are in nature superior to men, for the psalmist says that man was made "a little lower than the angels" (Psalm 8:5).
Angels are sent on missions of mercy to the children of God. To Abraham, with promises of blessings;...to David, while seeking divine wisdom in the court of a heathen king, or abandoned to become the lions' prey;...to Paul and his companions in the night of tempest on the sea;--thus holy angels have, in all ages, ministered to God's people. (The Great Controversy, 511, 512)
Reflection: Let's never forget that we do not fight alone, because every Christian has a guardian angel. These angels from heaven watch and will shield us from the power of Satan.