In the context, this verse seems out of place if interpreted to mean that we have freedom to eat whatever we want or to celebrate any days we want. Paul mentions various things that people teach to put us in bondage and steal away our salvation which comes from faith. Two of these things are food and holy days. We should not let someone dictate to us what kind of food to eat nor which days to celebrate.
We should ignore people who teach we must avoid certain foods or fast a certain way — we are not redeemed by such practices. This includes forms of asceticism as well as Jewish traditions and even pagan traditions. This is not to say that we shouldn't fast or have special dietary practices in our spiritual life — these can be helpful. The point is that our salvation does not require this nor should such practices be mandatory.
We should ignore people who teach we must celebrate certain days as holy days. This is not to say that we should avoid having special days, merely that we should not be forced to celebrate these days and that our salvation does not depend on our observance of such days.
Paul doesn't mention why one kind of food is bad and another good. Two possibilities suggest themselves...
The weak person must shun the foods in question for one of two reasons...
Two applications of this verse...
I know, and am persuaded by the Lord Jesus, that there is nothing unclean of itself: but to him that esteemeth any thing to be unclean, to him it is unclean. But if thy brother be grieved with thy meat, now walkest thou not charitably. Destroy not him with thy meat, for whom Christ died. (Romans 14:14,15)
Paul is probably referring to meat offered to idols and sold in the marketplace.
Paul doesn't mention why drinking wine is bad. This is in the same context as the other verses from chapter 14 so perhaps he is referring to wine offered to idols before it is sold in the marketplace.
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. (1 Corinthians 8:7)
If someone thinks it is a sin to eat food offered to an idol then it is a sin. Notice that they eat it because it is impolite in the social setting to say no and as a result they sin. We should not offer someone to someone that will make them sin.
One application of this is the use of alcohol. Some Christians think that any alcohol consumption is sinful. We should therefore not subject them to alcohol. Another reason for this is because some people may have had troubles with alcohol abuse and it is very unkind of us to tempt them.
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. (1 Corinthians 8:10)
It is hard to imagine a circumstance in which a Christian can in good conscience visit a temple of idolatry and join in the meal. Perhaps these temples had restaurants.
This raises the question of whether or not we should frequent businesses which conduct un-Christian business practices or even whether we should avoid certain activities altogether. Some examples...
I suppose if Paul didn't mind that Christians went to the local temple of idolatry restaurant for a meal he wouldn't mind any of the above — unless it stumbled a fellow Christian or led them into sin or tempted them to revert to their old sinful lifestyle.
This decree is from the Council of Jerusalem which occurred in 50 A.D. Paul wrote the first letter to the Corinthians after this so it seems odd he would contradict this decree.
This decree states that Gentile Christians are to abstain from eating food offered to idols. Jewish Christians didn't need this decree because they already avoided it.
This council was for the purpose of determining whether Gentile Christians needed to follow the Jewish law or whether they had complete freedom. The answer is odd.
They had freedom from the Jewish law except for...
They must obey the Jewish law in these areas...
I find it odd that they included fornication since the purpose of the council had nothing to do with this. Perhaps those Gentiles who thought they had freedom from the Jewish law saw no problem with practicing fornication. It is hard to imagine how they could be so dull-witted.
Whatsoever is sold in the shambles [butcher shop], that eat, asking no question for conscience sake: For the earth is the Lord's, and the fulness thereof. If any of them that believe not bid you to a feast, and ye be disposed to go; whatsoever is set before you, eat, asking no question for conscience sake. But if any man say unto you, This is offered in sacrifice unto idols, eat not for his sake that showed it, and for conscience sake: for the earth is the Lord's, and the fulness thereof. (1 Corinthians 10:25-28)
Christians don't need to inquire about the source of the food they purchase, about whether or not it was offered to idols.
I can imagine an awkward scenario. A Christian is invited to dinner and accepts. As they sit down to eat the host announces that the food was offered to idols. Now the Christian must refuse to eat.
Notwithstanding I have a few things against thee, because thou sufferest [allow] that woman Jezebel, which calleth herself a prophetess, to teach and to seduce my servants to commit fornication, and to eat things sacrificed unto idols. (Revelation 2:20)
They disobeyed the decree of the Council of Jerusalem in Acts 15:29. It seems that these two activities are in some way related. Perhaps the activities referred to are temple prostitution and ritual meals in these temples. To my mind these two activities are radically different in character but Paul connects them and feels the need to explain why fornication is so bad...
Meats for the belly, and the belly for meats: but God shall destroy both it and them. Now the body is not for fornication, but for the Lord; and the Lord for the body. What? know ye not that he which is joined to an harlot is one body? for two, saith he, shall be one flesh. (1 Corinthians 6:13,16)
One man esteemeth one day above another: another esteemeth every day alike. Let every man be fully persuaded in his own mind. He that regardeth the day, regardeth it unto the Lord; and he that regardeth not the day, to the Lord he doth not regard it. He that eateth, eateth to the Lord, for he giveth God thanks; and he that eateth not, to the Lord he eateth not, and giveth God thanks. (Romans 14:5,6)
Some think Paul is referring to the Sabbath, whether we should celebrate the Lord's day, Sunday, and whether it is OK for Christians to skip going to church on Sunday.
Christians have freedom about whether or not to follow Jewish customs regarding food and holy days. I suppose this also applies to Christian customs. For example, the Catholic Church decrees certain fasts and diet regulations and certain holy days and celebrations to be observed. But this passage seems to contradict this.
Paul writes this letter to oppose the idea that Christians must follow the Jewish law. This verse refers to the various Jewish feast days and holy days. He teaches that Christians are not bound by any of these Jewish laws and traditions.