The ICOC affirms the 66-book Protestant biblical canon as the complete and authoritative Word of God. The New Testament provides the pattern for Christian life and church order; the Old Testament provides the historical and prophetic foundation. No human tradition, creed, or extracanonical writing holds binding authority.

The ICOC's Restoration-movement heritage means that 'Scripture alone' is the formal principle: all doctrine, worship practice, and church order must be authorized by the New Testament, either explicitly, by example, or by necessary implication.