1st Corinthians 14:33

1st Corinthians 14:33 (see also Romans 1:30James 1:17; 1st John 1:5)
For God is not the author of confusion, but of peace, as in all churches of the saints. [KJV]

Outside the Church, God may judge and punish, which at times has included confusion, such as at Genesis 11:7-9, in which God confused the language of the people, and also at Exodus 23:27 and Judges 7:22 in which God caused confusion among the adversaries of Israel. However, inside the Church, God is not the author, source or origin of confusion. This also reinforces the fact that predestination is all that God does, but not that God does everything, because God is not the author of confusion within the Church. Therefore, this becomes a good proof-text to use against Determinism.

One Men’s Devotional states: “Are you tired? Discouraged? Fearful? Be comforted and trust God. Are you worried or anxious? Be confident in God’s power and trust His Holy Word. Are you confused? Listen to the quiet voice of your Heavenly Father. He is not a God of confusion. Talk with Him; listen to Him; trust Him. He is steadfast, and He is your protector…forever.” (Journey With God: For Men, emphasis mine)

​Question: If God is not the “author of confusion,” then how can it be said that God is the author of everything, through Determinism?

Answer: Confusion is something, and since God is not the author of it, it logically follows that God must not be the author of everything.

The Calvinistic, Westminster Confession of Faith: “God, from all eternity, did, by the most wise and holy counsel of his own will, freely, and unchangeably ordain whatsoever comes to pass: yet so, as thereby neither is God the author of sin, nor is violence offered to the will of the creatures; nor is the liberty or contingency of second causes taken away, but rather established.” (Westminster Confession of Faith, III. Of God’s Eternal Decree, emphasis mine) 

Does that include confusion? Remember that God is not the author of it. 

One Calvinist explains: “God is like the architect 
who’s signature appears at the bottom of every 
page of the blueprints because he has personally 
decided (and signed off) on every detail. But this 
does not necessitate that people cannot make 
choices; and to assume that it does, would be a 
mistake.” (CARM.org) In other words, this infers 
the Calvinist doctrine of Compatibilism. But what 
kind of “choices” do they make? Like a character
in a book?

I cannot help but conclude that Calvinists want it both ways. They want God to be the cause of everything, so that God can be “sovereign,” as they understand sovereignty, and yet many Calvinists simultaneously do not wish to concede that their logic also requires that God be the “author of sin.” So which is it? The answer from Calvinists is Compatibilism.

Laurence Vance: “The contradictory and confusing nature of God’s decrees as presented by the Reformed theologians rules out any possibility of God being the source of them. God ‘cannot deny himself’ (2 Tim. 2:13), and neither is he ‘the author of confusion’ (1 Cor. 14:33).” (The Other Side of Calvinism, p.297, emphasis mine)

Sometimes Calvinists will state that God is the primary cause of all things, though He is not necessarily morally responsible for what He causes, since He causes sin through secondary means.

​Calvinism is stretched thin, because while on the one hand, 
God decrees “whatsoever comes to pass,” on the other hand, 
He is not the author of whatsoever comes to pass, namely, 
sin. Thus, the future is fixed and settled by God’s alleged 
decree, but is not the author of some things, like confusion. 
God never tempts, but He has immutably decreed all 
temptations, including every failure and every success. 
Although it never entered God’s mind to command the act 
of child sacrifice (Jeremiah 32:35), God most certainly 
decreed it. That’s just too much gymnastics.

Here is an article that deals with that issue.