Docetism

Chapters 9-11 attack the specific heresy that Ignatius is concerned with: Docetism, the belief that Christ was not really human and did not really suffer, but only appeared to. Ignatius attacks this heresy with a passionate defense of the humanity of Christ, who "did eat and drink".

There is a pastoral reason for the vehemence of Ignatius' argument, even referring to the heretics as the "offshoot of Satan." Ignatius is suffering for the gospel, on the way to face martyrdom. He makes sense of this suffering by seeing it as a participation in the suffering and the passion of Christ. Yet, if Christ was not truly human, and his suffering not real, this makes a mockery of Ignatius' own suffering and faithfulness.

The letter concludes with the customary concern with love and unity.