Some examples of good shadows are: the shadow which is shade from trees (Job. 40:22); the protection of God's "wings" (Ps. 36:7); the belief that Peter's shadow would heal the sick (Acts. 5:15); that the earthly priesthood was a shadow of Christ's heavenly priesthood, and the tabernacle was a picture of the heavenly temple (Heb. 8:1-5); or that the Jewish sacrifices, repeated over and over, were a foreshadowing of the once-and-for-all sacrifice of Jesus for our sin (Heb. 10:1-13).
Evil shadows, on the other hand, are scary! They warn of the nearness of apparent danger. The most common of these found in the Bible is the "shadow of death." This phrase appears 19 times (Job 9x; Ps. 4x; Isa. 1x; Jer. 2x; Amos 1x; Mt. 1x; and Lk. 1x). The most familiar verse where this phrase is used is Psalm 23:4, which says, "Yea, though I walk through the valley of the shadow of death, I will fear no evil: for Thou art with me; Thy rod and Thy staff they comfort me." Satan, who according to Hebrews 2:14, has the power to take human life, should not be feared because he cannot exercise his power without the permission of God (Job 1:12-19; 2:1-6).
But, does this "shadow" actually represent something real? According to God's Word, the human soul, that part of us which is everlasting, never really dies. While the body dies, and unregenerated man is already dead spiritually (Jn. 5:24; Eph. 2:1-5), the soul of the righteous lives forever with the Lord (1 Thes. 4:13-18), and the unsaved soul will spend eternity in the Lake of Fire (Rev. 20:11-15). Therefore, "death's shadow" should not be a thing of dread unless you have never accepted Jesus Christ as your Lord and Savior. Trusting in the Jesus of the Bible, today, can remove all fear of the "shadow of death!"
It is helpful to me to remember that every shadow is formed by something blocking light. When it comes to shade, a tree is blocking the sun. When it involves Satan, we need to remember the Light behind him is God Almighty! Satan is allowed to "cast his shadow" only where God wills it. And, if it is God's will that the "angel of death's shadow" cross my path, because I am a child of God by faith in Jesus Christ, I have absolutely nothing to fear!
O death, where is thy sting? O grave, where is thy victory? The sting of death is sin; and the strength of sin is the Law. But thanks be to God, which giveth us victory through our Lord Jesus Christ" (1 Cor. 15:55-57)!!!