1 Corinthians 8

1 Paul wants to discuss idols, but he first digresses on the subject of knowledge. Everyone knows about something. Each person may know certain things better than those around him. However, such knowledge can lead to arrogance if not controlled. If we love others, we will use our knowledge to help them and not to become conceited.
2 Arrogant knowledge is evidence that a person does not have a godly perspective.
3 We already know that God knows the heart of every man, so there must be an unspoken conclusion to this argument. When we have a relationship with God, He will show us the secrets of our hearts and give us an appropriate perspective on our place in the world. With a better understanding of God and ourselves, we can use knowledge in a loving and godly way.
4 There are people who know (and believe) mythology, but if they become Christians they will come to the true knowledge that there is only one God.
5 At best, idols are merely objects, and at worse, they are used to worship demons (Isa 37:19, 1 Cor 10:20).
6 The Christian acknowledges that there is only one God. As is discussed elsewhere, God is made up of three "beings": Father, Son, and Holy Spirit. Here we see an example of how they work as one. The Father gives all things, and they are created through Jesus.
7 By comparison, then, an idol should mean nothing to a Christian. Even so, so people are superstitious about such things. A Christian with such superstitions is defiled in their own heart if they eat something that was dedicated to an idol.
8 Those Christians who know better know that God is not concerned if we eat such food or not. Whether or not the food was offered to an idol, it is still the same food. Since we do not honor the idol anyway, it should be immaterial what the food went through to get to our table. So whether we choose to eat or refrain from such food, our spirits are unaffected.
9 Yet, those who are not superstitious about their food need to be mindful of those who are.
10 The point is that the "weak" Christian is being encouraged to do things that make him feel guilty. The food itself is not harmful, but his lack of faith in eating it is (Rom 14:23). In addition, if a weak Christian begins to ignore his conscious, then he may begin to participate in behaviors that really are detrimental to his spiritual life.
11 Thus, this is an example of how our "superior" knowledge can do more harm than good.
12 Even worse, this use of knowledge has resulted in sin despite the fact that the original knowledge is not sinful.
13 What the difference is then is love. The Christian who has more freedom in Christ needs to be sensitive to those who are still bound by superstitions. In the case of food, Paul indicates that he would become a vegetarian for the sake of the weaker Christian's conscious. Giving up meat is no loss compared to the value of a Christian's relationship with God.

An example from the culture in the United States would be alcohol consumption. The Bible does not condemn moderate alcohol consumption (it does condemn drunkenness - 1 Cor 6:10, Eph 5:18). Yet, in many Christian circles, all alcohol consumption is condemned, and even non-Christians have the notion that all "good" Christians are teetotalers. Therefore, in this culture, for a Christian to use his biblical freedom to consume non-intoxicating quantities of alcohol would cause others to become uncomfortable. If he encouraged a "dry" Christian to drink, he would likely be violating their conscious and cause the non-drinker to sin in his own heart. Thus, out of love, most Christians who do not feel guilty about moderate alcohol consumption refrain for the sake of their fellow Christians.