Howbeit there is not in every man that knowledge. — The Apostle had admitted that in theory all have knowledge which should render the eating of things offered to idols a matter beyond question; but there are some who, as a matter of fact, are not fully grown — have not practically attained that knowledge.
Some with conscience of the idol unto this hour eat it as a thing offered unto an idol. — Better, some, through their familiarity with the idol, even up to this time eat it as offered to an idol.
The weight of MSS. evidence is in favour of the word “familiarity” instead of the word “conscience,” and joins “even up to this time,” not with “eat,” but with the previous words. Thus the allusion is to heathen converts who, from their previous lifelong belief in the reality of the idol as representing a god, have not been able fully to realise the non-existence of the person thus represented, though they have come to believe that it is not God; and therefore, they regard the meat as offered to some kind of reality, even though it be a demon. (See 1 Corinthians 10:20-21.) The Apostle admits that this is a sign of a weak conscience; and the defilement arises from its being weak.