7 Notwithstanding, that knowledge is not in every man: For some with consciousness of the idol to this hour eat it as a thing offered to an idol; and their conscience being weak is defiled.  
1 Corinthians 8:7 Cross References - TKJU
Romans 14:14
14 I know, and am persuaded by the Lord Jesus, that there is nothing unclean of itself: But to him that esteems anything to be unclean, to him it is unclean. 
Romans 14:22-23
1 Corinthians 1:10-11
10 Now I beseech you, brethren, by the name of our Lord Jesus Christ, that you all speak the same thing, and that there be no divisions among you; but that you be perfectly joined together in the same mind and in the same judgment. 
11 For it has been declared to me concerning you, my brethren, by those who are of the house of Chloe, that there are contentions among you. 
1 Corinthians 8:9-10
1 Corinthians 10:28-29
28 But if any man says to you, "This is offered in sacrifice to idols", do not eat it for his sake that told it, and for conscience sake: For "the earth is the Lord's, and the fullness of it": 
29 I do not say your own conscience, but that of the other: For why is my liberty judged by another man's conscience?