The Heresy of Patripassionism
This is the theological error dealing with the very nature of the Godhead which in orthodox christianity is understood in the Trinitarian formula. It states that the Father became incarnate, suffered, and died ( linking it closely with Modalism ) confusing the persons of the Trinity.
We understand that both the Father, the Son, and the Holy Spirit are co-eternal and co-substantial in their being while being three persons. This precludes the heretical notion of patri ( father ) passionism ( suffering ).