Lest Satan should take advantage of us; for we are not ignorant of his devices.
First, let’s consider the context of this passage. The apostle Paul was telling the Corinthians to welcome back a man who had sinned but then repented. Paul wanted to make sure the man was not “swallowed up with too much sorrow,” so he urged them to “reaffirm your love to him” (2 Corinthians 2:7-8).
Paul knew that Satan would use every opportunity he could to foster unforgiving attitudes to divide the Church and to try to discourage members into giving up. Division and discouragement are just two of Satan’s many “devices” that we must be aware of and guard against. Ephesians 6:10-20 describes the spiritual armor we can use to defend against Satan’s attacks.