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)
The Calvinistic, Westminster Confession of Faith, states: “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.
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.”
John Calvin comments: “A word like ‘author’ must be understood. This is a most valuable sentence for it teaches us that the only way we can serve God is by being people who love peace, and are eager to have it. So where people want to quarrel, we can be quite sure that God is not reigning there.” (Calvin’s Commentaries: The First Epistle of Paul the Apostle to the Corinthians, p.305, emphasis mine)
It is unclear how an admission that “God is not reigning there” can square with exhaustive Determinism.
Here is an article that deals with that issue.