Lest Satan should get an advantage of us: for we are not ignorant of his devices.
Literally, 'That we may have no advantage gained over us by Satan'-namely, by letting one member be lost to us through despair, we ourselves furnishing Satan with the weapon, by repulsive harshness to one now penitent. The loss of a single sinner affects all. Paul had 'delivered' the offender 'to Satan for the destruction of the flesh, that the spirit might be saved' (1 Corinthians 5:5). Satan sought to destroy the spirit also: to let him do so, would be to let him overreach us.
Not ignorant of his devices. "Ignorant" and "devices" are akin in sound and root х noeemata (G3540) agnooumen (G50)]: we are not without knowledge of his knowing schemes: here to trip up one by excessive grief, as before by licentiousness: to make not only men's lusts, but their very repentance, his instrument of destruction, under the guise of religion (Ephesians 6:11).