For I know nothing by myself; yet am I not hereby justified: but he that judgeth me is the Lord.
By myself. Translate, 'I am conscious to myself of no (ministerial) unfaithfulness.'
Yet am I not hereby justified - therefore conscience is not an infallible guide. Paul did not consider his so. He had a good conscience (2 Corinthians 1:12); but God might see unfaithfulness in him which his own conscience could not yet accurately detect. Much of his labour might prove "stubble" in the testing day. "Justified" here refers to sanctifying righteousness. Of his justification he has no doubt (Romans 5:1); but of the degree of his sanctifying righteousness he cannot be infallibly sure until the judgment day, when he will gain or lose reward accordingly (1 Corinthians 3:14-15).