What does it mean when the Bible says that an evil spirit was sent by God to torment Saul (reference 1 Samuel 16:14-15 [14] But the Spirit of the LORD departed from Saul, and an evil spirit from the LORD troubled him. [15] And Saul's servants said unto him, Behold now, an evil spirit from God troubleth thee.
See All...)?

1 Samuel 16:14-15 [14] But the Spirit of the LORD departed from Saul, and an evil spirit from the LORD troubled him. [15] And Saul's servants said unto him, Behold now, an evil spirit from God troubleth thee.
See All... states, "But the Spirit of the LORD departed from Saul, and an evil spirit from the LORD troubled him. And Saul's servants said unto him, Behold now, an evil spirit from God troubleth thee."

Some of the most difficult passages in scripture are those that show God using the devil or evil spirits for His purpose. We know that God is not the cause of wickedness, so it goes against our understanding to think of Him sending evil spirits hither and yon to do His bidding. Yet, we examine scripture and there they are. Let us see if we can make sense of this biblical teaching.

1. First, we must understand that God is not the source of wickedness. The "evil" He creates in Isaiah 45:7I form the light, and create darkness: I make peace, and create evil: I the LORD do all these things.
   See All... refers to bad things like earthquakes and floods, not to sin or wicked acts (this verse is covered in another question and answer). The Bible teaches that sin originates from the devil (1 John 3:8He that committeth sin is of the devil; for the devil sinneth from the beginning. For this purpose the Son of God was manifested, that he might destroy the works of the devil.
   See All...). He is also the father of the lie and was a murderer from the beginning (John 8:44Ye are of your father the devil, and the lusts of your father ye will do. He was a murderer from the beginning, and abode not in the truth, because there is no truth in him. When he speaketh a lie, he speaketh of his own: for he is a liar, and the father of it.
   See All...). On the other hand, God cannot be tempted with evil or wicked acts and He does not tempt any man to commit these acts (James 1:13-14 [13] Let no man say when he is tempted, I am tempted of God: for God cannot be tempted with evil, neither tempteth he any man: [14] But every man is tempted, when he is drawn away of his own lust, and enticed.
   See All...). God is holy and all that springs forth from Him is pure and good.
2. Second, though God is not the source of wickedness, He often uses the wicked to perform His own purpose. Psalm 76:10Surely the wrath of man shall praise thee: the remainder of wrath shalt thou restrain.
   See All... states, "Surely the wrath of man shall praise thee: the remainder of wrath shalt thou restrain." Here we learn that God will take man's wrath toward Him and turn it into praise. That wrath which is not to be turned into God's praise will be restrained.

But how can God use the devil and evil spirits to do His bidding? Perhaps a biblical study of the cause of death would help at this point. On one hand, God is clearly the cause of death. In Deuteronomy 32:39See now that I, even I, am he, and there is no god with me: I kill, and I make alive; I wound, and I heal: neither is there any that can deliver out of my hand.
See All..., He declares, "I kill, and I make alive." Hannah, in her prayer of praise, said, "The LORD killeth, and maketh alive: he bringeth down to the grave, and bringeth up" (1 Samuel 2:6The LORD killeth, and maketh alive: he bringeth down to the grave, and bringeth up.
See All...). Exodus 12:23For the LORD will pass through to smite the Egyptians; and when he seeth the blood upon the lintel, and on the two side posts, the LORD will pass over the door, and will not suffer the destroyer to come in unto your houses to smite you.
See All... tells us concerning the first Passover, "For the LORD will pass through to smite the Egyptians." Certainly, God is in charge of taking life.

However, on the other hand, Hebrews 2:14Forasmuch then as the children are partakers of flesh and blood, he also himself likewise took part of the same; that through death he might destroy him that had the power of death, that is, the devil;
See All... tells us that Christ came to die on the cross that He might "destroy him that had the power of death, that is, the devil." The next verse say that the devil holds the lost in bondage through the fear of death. But the problem is clear. If God is in charge of death, how can the devil have the power of death? The answer explains a lot about how God uses the world of the wicked to do His bidding.

The devil by nature is a murderer (John 8:44Ye are of your father the devil, and the lusts of your father ye will do. He was a murderer from the beginning, and abode not in the truth, because there is no truth in him. When he speaketh a lie, he speaketh of his own: for he is a liar, and the father of it.
See All...). His rebellion against God changed his character and has made him a force that naturally kills and destroys all that comes under his power. In Revelation 9:11And they had a king over them, which is the angel of the bottomless pit, whose name in the Hebrew tongue is Abaddon, but in the Greek tongue hath his name Apollyon.
See All..., he is called Abaddon and Apollyon. Both names mean Destroyer. Paul understands that someone may be delivered "unto Satan for the destruction of the flesh" (1 Corinthians 5:5To deliver such an one unto Satan for the destruction of the flesh, that the spirit may be saved in the day of the Lord Jesus.
See All...).

We see this principle in operation in Job. When God turns Job over to Satan the second time, He states, "Behold, he is in thine hand; but save his life" (Job 2:6And the LORD said unto Satan, Behold, he is in thine hand; but save his life.
See All...). If God had allowed him to do so, Satan would have killed Job. Earlier in the story, God did allow Satan to kill the sons and daughters of Job (Job 1:18-19 [18] While he was yet speaking, there came also another, and said, Thy sons and thy daughters were eating and drinking wine in their eldest brother's house: [19] And, behold, there came a great wind from the wilderness, and smote the four corners of the house, and it fell upon the young men, and they are dead; and I only am escaped alone to tell thee.
See All...). So, who killed the children of Job? You say, Satan. But even this is not so easy. After they were killed, Job said, "the LORD gave, and the LORD hath taken away; blessed be the name of the LORD" (Job 1:21And said, Naked came I out of my mother's womb, and naked shall I return thither: the LORD gave, and the LORD hath taken away; blessed be the name of the LORD.
See All...). He gave God the credit for taking his children (also the cattle and other possessions). And, if we reflect on it, we can see that both are true. Satan killed Job's children but God was responsible for allowing them to be killed. He took them away.

So, what about the sending of evil spirits by the Lord? This may be more common in scripture than you think. In Psalm 78:49He cast upon them the fierceness of his anger, wrath, and indignation, and trouble, by sending evil angels among them.
See All..., God judged Israel "by sending evil angels among them." In Judges 9:23Then God sent an evil spirit between Abimelech and the men of Shechem; and the men of Shechem dealt treacherously with Abimelech:
See All..., "God sent an evil spirit between Abimelech and the men of Shechem." In 1 Kings 22:22And the LORD said unto him, Wherewith? And he said, I will go forth, and I will be a lying spirit in the mouth of all his prophets. And he said, Thou shalt persude him, and prevail also: go forth, and do so.
See All..., God sent a "lying spirit" in the mouth of the false prophets to send Ahab to his death. In the passage in question (1 Samuel 16:14-15 [14] But the Spirit of the LORD departed from Saul, and an evil spirit from the LORD troubled him. [15] And Saul's servants said unto him, Behold now, an evil spirit from God troubleth thee.
See All...), God removed His Spirit from the disobedient Saul. This opened the door for an evil spirit to come and torment Saul. Though in this passage, it is only the servants of Saul that said the evil spirit was from the Lord, in other passages (1 Samuel 18:10And it came to pass on the morrow, that the evil spirit from God came upon Saul, and he prophesied in the midst of the house: and David played with his hand, as at other times: and there was a javelin in Saul's hand.
See All...; 1 Samuel 19:9And the evil spirit from the LORD was upon Saul, as he sat in his house with his javelin in his hand: and David played with his hand.
See All...), the text states that the evil spirit came from the Lord.

What we see in these passages follows a pattern. When God removes His protective hand, he often turns the person over to Satan for destruction or to an evil spirit for torment. The devil and the evil spirits do the work, but God has allowed them to do what come natural to them for His own purpose. I know that some will have trouble with this concept, but it is thoroughly established in scripture. God does not commit wickedness, but He uses the wicked for His purpose. In the end, God will have His glory. How much better it is for us to submit to Him and obey Him willingly.

Thank you for the question. I hope this helps you understand the passage.