When we think of culture it is helpful to divide the topic as follows.
For us in Japan, most obviously, this means eating with chopsticks and taking our shoes off at the door. It also includes less obvious things, such as not ripping the paper off a present, restraint in accepting an invitation, filling the guest’s teacup only 2/3 full, and so on.
Because the Japanese have adopted Western dress, some misinterpret this as meaning that they dress in the Western way. This is far from the truth.
Generally speaking, the Japanese standards of modesty are higher and more sensitive than in the West. There is the need for men especially to wear black, not only for funerals but for anything formal such as weddings and graduations, and a dark colour for business and other important meetings.
Some missionaries find it hard at first to accept the need to wear a suit and tie on various occasions, because they judge the meaning of it from the point of view of their own culture. Some dress in jeans and a T-shirt, whatever the occasion, thinking that informality is an expression of sincerity. Actually the opposite is the case. It is seen as an expression of disrespect, and they are not respected for this. What you wear is an expression of the seriousness of your commitment to the business in hand.
This is an area where we do not adapt to culture. The Bible teaches us that the world is far from God in its standards of right and wrong, and warns us not to conform to it. Culture in every country is tainted by sin. This includes such things as drama, dance and music, as far as they express the original thought, moral standards and worldview of that people. To become a vehicle for the gospel, not only the content of the art form, but also the ethos must undergo change, and in some instances this may not be possible or advisable. Some of it is steeped in immorality. A lot of it is a teaching vehicle to pass on beliefs that are incompatible with Christianity. Much of it is performed as an offering to the gods, or to call on the spirits, to “keep them happy” or to gain certain benefits. Over-enthusiastic, indiscriminate participation in these aspects of culture, to make the gospel acceptable, or to prove that you are “one with the people”, can result in a distortion of the truths we are trying to get across.
In terms of behavior, in Japan for example, telling lies is acceptable if it suits your personal convenience. A certain amount of drunkenness is not frowned on. Gluttony is a fun thing. The Bible speaks out plainly against these and many other cultural norms, and we have an obligation to teach accordingly, as we help people to repentance. We find that even in a non-Christian culture, some moral standards are higher than those found in the Christian church in our homelands! Respect for authority and for the aged are two examples. These must not be undermined in the name of a false “equality” that we may think comes from the Bible, but is really an expression of our own cultural background
Religion in its various forms is one of the expressions of culture, but compromise is absolutely forbidden to us. Of course this doesn’t mean we treat peoples’ beliefs with disrespect. But in this age of tolerance, we will be frowned upon for our stand that there is only one truth, one God, and one way of salvation.
Japan has sometimes taken the false position that Shinto is “culture, not religion”, and therefore participation can be forced on people without seeming to violate the constitution that guarantees freedom of religion. Some people have been fooled by this distortion of words. The big Shinto festivals are fascinating; the small local ones are fun times. Buddhist ancestor worship is beautifully presented. It can be easy to forget the Bible warning that behind all expressions of false worship is the activity of evil spirits. (Satan himself transforms into an angel of light, we are warned.) It is arguable that one of the reasons that Japan is so unresponsive to the gospel, is that too many Christians compromise on “small” issues of idolatry. (Would anyone be happy to leave “just a little” cancer behind?).
To quote an Australian Aboriginal leader facing similar issues in his work for the Lord: “If there’s something that doesn’t chime with the Word of God in our tribal laws, then that needs to go.” (“Eternity” newspaper, Feb. 2018)