"For He shall give His angels charge over thee, to keep thee in all thy ways" (Psalm 91:11).
God has created "an innumerable company of angels" (Hebrews 12:22), and there are many references to them in both Old and New Testaments, but few living men or women have ever actually seen real heavenly angels--or, at least, recognized them as such. We may "have entertained angels unawares" (Hebrews 13:2), for they can assume the appearance of men on occasion, but normally they are invisible to human eyes.
Nevertheless, they are there! Furthermore, they are "all ministering spirits, sent forth to minister for them who shall be heirs of salvation" (Hebrews 1:14). God has given them charge over us--that is, over each believer "that dwelleth in the secret place of the most High" (Psalm 91:1). They "excel in strength, that do His commandments, hearkening unto the voice of His word" (Psalm 103:20).
Wide is the variety of His commandments with respect to angelic ministry to believers. "The angel of the LORD encampeth round about them that fear Him, and delivereth them. . . . They shall bear thee up in their hands, lest thou dash thy foot against a stone" (Psalms 34:7; 91:12).
Not only physical protection but also guidance and encouragement are angelic ministries. When a believer dies, angels translate his spirit to the Lord's presence (Luke 16:22; II Corinthians 5:8), and we can look forward then to meeting and thanking them personally as we come to understand better all their ministries on our behalf during our lifetimes. They are keenly concerned with our salvation and spiritual progress, "which things the angels desire to look into" (I Peter 1:12). Finally, "When the Son of man shall come in His glory," He will bring "all the holy angels with Him" (Matthew 25:31) as He judges the world. HMM