Some times we ascribe more power to Satan than he actually has, and less to God than he actually has.
1st Samuel 16:14 KJV
But the Spirit of the LORD departed from Saul, and an evil spirit from the LORD troubled him.
they were attributing power to the correct person. So now that I have you completely confused, let's take a look at the scripture and try to discern what is really being said.
First let's take 'But the Spirit of the LORD departed from Saul' and see what is being conveyed here. In the previous verse:
1st Samuel 16:13 KJV
Then Samuel took the horn of oil, and anointed him in the midst of his brethren: and the Spirit of the LORD came upon David from that day forward. So Samuel rose up, and went to Ramah.
we are told that David was anointed and the Spirit of God came upon him. Which apparently prior to Jesus crucifixion only inhabited one person at a time, and that is the reason it is then said that the Spirit left Saul.
Be that as it may it is the second part of verse 14 in which the misunderstanding occurs.
"and an evil spirit from the LORD troubled him", So are there any other Scriptures which will help us to understand this? Let's start with:
Genesis 1:1 KJV
In the beginning God created the heaven and the earth.
next let us consider:
Joh 1:1 through 3 KJV
1 In the beginning was the Word, and the Word was with God, and the Word was God.
2 The same was in the beginning with God.
3 All things were made by him; and without him was not any thing made that was made.
If we combine these Scriptures we must accept that Satan and all the fallen Angels were in fact created by God, and therefore all things "Good and Bad" were made by God.
So how did the evil Spirits come to be?
God did not create Evil Spirits! God created good Spirits (in this case Angels) who by their own choice became Evil.
Revelation 12:7 through 9 KJV
7 And there was war in heaven: Michael and his angels fought against the dragon; and the dragon fought and his angels,
8 And prevailed not; neither was their place found any more in heaven.
9 And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him.
Satan does not have a Kingdom, but he does have a band of Angels who were co-conspirators in his rebellion against God. These angels are alternately known as demons, and one of these is what is referred to in verse 14, and since they were created by God to say that they are a an evil spirit of the LORD is totally correct the operative word being "evil".
Another question that has crossed my mind concerning this Scripture is did God inspire the writer of Samuel to use those words in order to draw our attention to the fact that when the Spirit of the Lord is not within us that there is an evil spirit just waiting for the chance to take over?