1 Corinthians 8:4-13 (KJV)
 As concerning therefore the eating of those things that are offered in sacrifice unto idols, we know that an idol is nothing in the world, and that there is none other God but one.  For though there be that are called gods, whether in heaven or in earth, (as there be gods many, and lords many,)  But to us there is but one God, the Father, of whom are all things, and we in him; and one Lord Jesus Christ, by whom are all things, and we by him.
 Howbeit there is not in every man that knowledge: for some with conscience of the idol unto this hour eat it as a thing offered unto an idol; and their conscience being weak is defiled.  But meat commendeth us not to God: for neither, if we eat, are we the better; neither, if we eat not, are we the worse.
 But take heed lest by any means this liberty of yours become a stumblingblock to them that are weak.  For if any man see thee which hast knowledge sit at meat in the idol's temple, shall not the conscience of him which is weak be emboldened to eat those things which are offered to idols;  And through thy knowledge shall the weak brother perish, for whom Christ died?  But when ye sin so against the brethren, and wound their weak conscience, ye sin against Christ.  Wherefore, if meat make my brother to offend, I will eat no flesh while the world standeth, lest I make my brother to offend.
1 Corinthians 10:18-22 (KJV)
 Behold Israel after the flesh: are not they which eat of the sacrifices partakers of the altar?  What say I then? that the idol is any thing, or that which is offered in sacrifice to idols is any thing?  But I say, that the things which the Gentiles sacrifice, they sacrifice to devils, and not to God: and I would not that ye should have fellowship with devils.  Ye cannot drink the cup of the Lord, and the cup of devils: ye cannot be partakers of the Lord's table, and of the table of devils.  Do we provoke the Lord to jealousy? are we stronger than he?
In 1 Corinthians 8, Saint Paul seems to be saying that there is nothing wrong with eating food sacrificed to idols because the god that the food was sacrificed to does not exist, but that we should not do it if a Christian brother sees us and thinks that the god exists because of that. However, in 1 Corinthians 10, Saint Paul states that it is wrong to eat food sacrificed to idols because the idols are demons. Does Paul contradict himself, or how can these passages be reconciled?