What is the specific doctrine that affected in the time of Ignatius of Antioch?

The specific doctrine that affected Ignatius of Antioch during his time was the rise of Gnosticism. Gnosticism was a religious movement that emphasized secret knowledge and spiritual enlightenment as the path to salvation, often rejecting the physical world as inherently evil. Ignatius of Antioch, as a prominent early Christian leader, wrote several letters addressing the dangers of Gnosticism and emphasizing the importance of orthodox Christian beliefs and practices.

Ignatianism