First of all, where in the Bible does it say that as believers, "we have to follow our own respective cultural values" (American, Indian, African, Chinese etc)? From my reading of God's word, I have not come across any principle which support this idea. Please prove me wrong if you can.
Second, I'm not against following our own cultural values, AS LONG AS THEY ARE IN LINE WITH GOD'S WORD". The Bible emphasizes only one culture for us as believers and that culture can be seen in Matthew 5-7 where it talks about the Kingdom of God. We are citizens of that Kingdom. We need to understand that even though God may have chosen us to come from different races and cultures, all believers are seen as the same by God- as one body, the Church. God does not make such distinctions between races and cultures for believers, so why should we? Many times, we focus on the wrong things in life like comparing Western culture with Indian culture. You will tend to find both good and bad things in both. If you find Indians following Western culture, esp wearing suits and eating Western food, what is wrong with that? All food is the same composed of the same substances- carbohydrates, proteins, and fat. Just because people cook food in a different way doesn't give anyone the right to judge one culture to be a superior choice over another. Every person will have their own likings, so we need to learn to respect that and not be critical of someone who doesn't follow one's own cultural background. At the same time, if you look at the bad things in each culture, you will find things which will of course be against God's Word (for example, in the West, premarital relationships, divorce, homosexuality, abortion are things which many people think are ok, which we know clearly goes against God's Word). However, even in India, these issues are starting to be a problem also. I've come across people who have made foolish statements to actually blame the West for that also. Sin originated from Adam, not the West :) So that virus of sin is in every human being regardless of race or culture. No earthly culture or race is perfect. We know that all have sinned and come short of the glory of God (Romans 3:23).
I just wanted to end by saying that we should be focused on one thing i.e. identifying ourselves in Christ instead of trying to identify ourselves in the worldly cultures. As our denomination calls itself- Brethren/Verbad (Separatist), we should be separating ourselves from the rest of the world's views and teachings and instead implement God's Word in our lives. I believe that is what God has called us to do. When we implement God's Word in our lives and display His love, that is how unbelievers will be impacted. Let's always focus on that in our lives.