When Ibrahim(as) raised the knife, it was not the animal that was being tested. It was the man holding it. Eid al-Adha is a reminder that sacrifice is not meant to end with the ritual, but to begin with it.
Gaining the true cognition of God has never been simple—and perhaps never more easily prone to error than today. Could God have left us to wander in uncertainty, or has He arranged a means to guide us to His true recognition?