Simply, the Credo position is left with uncertainty and pure subjectivism on the matter. When you say some will be 6 years old, but others who grow up in covenant homes may be 12 (not to speak of some who wait until they are 18) before they get to such and such a point of reason and maturity to take the Lord’s Supper, then you have begun to do what Paul opposed in I Corinthians: to make classes of Christians; to categorize the body; to dis-unify the oneness of the Unbroken body of our Lord. So, this becomes very problematic indeed.
