A lot of people today are talking about contextualization as a fancy way to justify targeting the subset of the population they like best. They say we need to contextualize the gospel and the church into punk rock culture, or elite urban culture, or artsy hipster culture, or rich suburban culture, in order to reach those groups of people. But in such cases, contextualization can be a sophisticated way of marketing the gospel by catering to the tastes and preferences of a certain subculture, just as we market any other product. The problem is, the gospel is never given the opportunity to demonstrate its power in bringing different kinds of people together.
Biblical contextualization, on the other hand (see 1 Cor. 9:1-23), has to do with avoiding cultural practices that genuinely offend others. It aims to remove all unnecessary offense from the gospel.
In other words, contextualization is not as much about dressing up the church so that it appeals to the tastes of a certain population as it is about giving up cultural practices that offend people who belong to another culture, so that we don’t distract them from the genuine offense of the gospel.
Of course, contextualization also includes adopting whatever cultural practices are necessary in order to effectively communicate the gospel to members of another culture, such as speaking the same language, abiding by expected customs, and directly engaging the worldview and beliefs of the people one is evangelizing.