
I had a conversation some time ago with a patient that went something like this:
Proposition A. “God and the Devil are the same person.”
Why?
Proposition B. “People blame God for some things and they say the Devil caused other things.”
So it’s like two sides of the same coin. It made absolutely no sense to me. So in making conversation, it was something like this: God causes storms and illness, and Satan causes storms and illness. If the we have the same effect, we must have the same cause. If she’s right, then there no hope, because how can you have a God who judges evil if He is the source of the evil? How can God consign His own being to Hell? It just doesn’t make sense when you start to think through it. This does not solve the problem of good and evil, and it does not satisfy the issue that we know in our hearts.
Proposition B above is often applied to acts of nature or natural evil for which there is no human cause. i.e, storms, illness, freak accidents. But what about personal evil? Stuff we are tempted to do, or is done to us? If God and the Devil are the same, is there good and bad? Right and wrong? No, because they all come from the same source. And this violates our own sense of justice. If we have a sense of justice, then justice must be a real thing. But our sense of justice can’t be greater than God’s, can it? So God must be more just, and thus he cannot also be anti-justice at the same time. That violates the law of non-contradiction.
If we were only to take the proof of Proposition B, we might be tempted to accept Proposition A. However, there is far more proof to consider against Proposition A. While it is true that natural evil can come from Satanic influence (See Job 1) we also know that God uses catastrophic weather to judge evil (The Flood of Genesis 7). God sends plagues, causes the sun not to shine, parts the seas, and raises the dead. Satan on the other hand is known to afflict individuals (Job again is the example), and torments people. By his work, whole nations can suffer. David was tempted once to conduct a census, and because he did, God judged him for not trusting His faithfulness to sustain the nation, and offered David a choice of three judgments (this is in 2 Samuel). But Satan could not plague a whole nation, or send a flood. The two, God and Satan, may do similar things, but is a difference in scale. God can destroy the earth with a flood in judgment for sin. Satan can afflict a person with illness to tempt him to rebuke God. It’s very different after all.
And this doesn’t account at all for moral evil. Since we have a sense of justice, we know there is a difference between right and wrong. Every time we watch a movie or TV show, we know who the good guys are and who the bad guys are. It’s not hard. We can detect moral failure a mile away. With all of that skill, there must be some opposition between good and evil. They cannot come from the same place.
Also, Proposition A represents, though I doubt the speaker could articulate it, what is known as dualism. The Eastern religion of Taoism is probably the best articulation of this idea.

The white and the black portions represent good and evil, but both together form a whole. It was also popularized in Star Wars as the two sides of the force. However, in Star Wars, they never clearly represent it, as good is always implied to be the better way. That point of view doesn’t make sense in Taoism, as good and evil are both equal and equally powerful. This is contrary to Christian thinking, as it is very clear that God, the Creator, is uncreated Himself, and all things, even Satan, are created beings, making them inferior to Him.
Because God is the Creator, He has the authority to determine what is right, which necessarily are all things that agree with His nature. Everything that is contrary to His nature is considered evil. The universe declares the glory of God. Even without the Bible you can know that God is infinite, and infinitely creative. That He created surpassing beauty and wonder in the world around us. Even in us, He created beauty and grace, as we can tell between beauty and ugliness. When you read His word you find that God is a God of grace and mercy, forgiving sin and desires relationship with human beings through His Son, Jesus Christ. God wants all that is best for you, and is a ready refuge in times of trouble.
Satan on the other hand is consistently depicted as one who wishes you harm, wants you to reject God, and even in your own heart, you know there is always an influence desiring to tempt you away from what is good for what is sinful or evil.
How can God both encourage you to be better, and tempt you to be worse? Whose schizophrenic here?
I think it’s obvious that both Propositions are false. The first because it simply doesn’t fit the facts as we understand them, and the second because there is a vast difference in scale between “acts of God” and Satan’s schemes.