John Calvin Commentary 2 Corinthians 2:11

"that no advantage may be gained over us by Satan: for we are not ignorant of his devices." — 2 Corinthians 2:11 (ASV)

That we may not be taken advantage of by Satan. This may be viewed as referring to what he had said previously regarding excessive sorrow. For it is a most wicked deception of Satan when, depriving us of all comfort, he swallows us up, as it were, in a gulf of despair; and this is the explanation given by Chrysostom.

I prefer, however, to view it as referring to Paul and the Corinthians. For there was a twofold danger that threatened them from the stratagems of Satan—if they were excessively harsh and rigorous, or, on the other hand, if dissension arose among them.

For it very frequently happens that, under the guise of zeal for discipline, a Pharisaical rigor creeps in, which hurries the miserable offender to ruin instead of curing him. However, in my opinion, he speaks rather of the second danger; for if Paul had not to some extent favored the wishes of the Corinthians, Satan would have prevailed by kindling strife among them.

For we are not ignorant of his devices. That is, “We know, because the Lord has warned us, that one stratagem he carefully resorts to is that when he cannot ruin us by open means, he surprises us when we are off our guard by making a secret attack.”

Therefore, since we are aware that he attacks us with indirect schemes and assails us with secret plots, we must be very vigilant and careful that he may not injure us from any direction.

He uses the word devices in the sense in which the Hebrews use the term זמה (zimmah). However, it is used here in a negative sense, meaning artful schemes and plots. These should not be unknown to believers, and indeed will not be, if they surrender themselves to the guidance of God’s Spirit.

In short, since God warns us that Satan employs every means to deceive us, and also shows us the methods by which he may practice this deception, it is our responsibility to be on the alert, so that Satan may not have a single opening to creep through.