What is Paul saying in 2 Corinthians 11:2 about the church being engaged to Christ?
Paul applies the ancient espousal custom, in which a father arranged his son's engagement. He made the engagement between the body of Christ and Christ, its head, awaiting the wedding that will one day transpire in glory. The Corinthians, as members of that body, are warned to keep minds uncorrupted from the simplicity in Christ.
Les explains that in ancient practice a father would find the appropriate bride for his son, make all arrangements, and consummate the espousal—what we would call the engagement. Paul takes that same concept and says he has made the engagement between the body of Christ and Christ, the head of the body, in lieu of the wedding that will one day transpire in glory. Les holds that the body of Christ is the bride, not Israel, because Paul writes this to the Corinthians, who are members of the body of Christ. In verse 3 Paul fears that, just as the serpent beguiled Eve through subtlety, their minds should be corrupted from the simplicity that is in Christ. Les connects this to Adam and Eve as the first ordained human family, where God made the man the head of the woman, and to Ephesians 5, where Paul draws the analogy between a husband's relationship with his wife and Christ's relationship with the Church.
For I am jealous over you with godly jealousy: for I have espoused you to one husband, that I may present you as a chaste virgin to Christ.