Until driven to the work of expounding and defining, they have never suspected their ignorance upon matters with which they professed themselves altogether familiar . The Biblical doctrine of the Trinity was thoroughly searched out in reaction to Gnostic and Arian heresies. The precious doctrine of Justification by Faith alone was most clearly vindicated in answer to Pelagian works righteousness and the corruptions of Romanism. So in the sense which heresy is used by God as a challenge, or test, these trials ultimately under His providential hand, bring blessing and maturity for the church. It serves as a winnowing fork that separates wheat from chaff.
Heresy is the fruit of unfaithfulness.
It is God's judgment on a backslidden and cowardly church. Disunity of mind and doctrine is evidence of sin in the church. As with the sin of Achan, this sin cripples the entire camp. We must remember that God assigns duties, not only to individuals, but also to corporate bodies of people, whether they be families, nations, or churches. Daniel and Ezra identified themselves before God as part of a people in rebellion against Him.