There is a saying, "when in Rome, do as the Romans do". This saying has mixed value. On the one hand, Christians are not morally bound to the culture, but to God. Thus, when in Rome, you absolutely should not do any sinful things as the Romans do them. But what about when their customs are not sinful?
Let me pose a question to you that may illustrate today's point. How would you feel if I told you about a man who ate a dog? Or a cat? Or a horse? Even though rabbits are common in cat and dog food, I have often found that, at least here in Britain, many people are offended even at the notion of eating a rabbit. The animals I have just described are seen as being, for lack of better term, almost sacred in our culture. Dogs and cats especially are "not" food in our culture.
Now, imagine you're trying to witness to a Hindu. "Hey, come to Christ, you'll receive forgiveness for your sins, and you'll inherit eternal life". As you deliver that message, you take yet another bite of a cheeseburger. To a Hindu, you may have just done the equivalent of eating a dog right in front of him. Thus, you have just done something he sees as horribly offensive while delivering the Gospel. Similarly, a Chinese Christian might lose a potential British convert by eating dogs.
My brethren, Biblically speaking, all things are food. You can be a vegetarian, you can eat animal products, you can eat any animal you can obtain and cook safely and legally. If you live somewhere it's culturally acceptable to eat cows, and doing so will offend nobody, then by all means eat that burger. But the unfortunate truth is, Christian liberty is most offensive to those who do not have it. If you try to witness to someone who sees you doing something our God says we're allowed to do, but their conscience tells them we're not, you have tarnished the Gospel almost as much without sin as you would have done with it.
Thus, there is great benefit to the phrase "when in Rome, do as the Romans do". When in Rome, it is absolutely acceptable, almost even necessary, to become as Roman as you possibly can. Without sin, of course, but at the same time, becoming all things to all people minimises the offence caused by a naturally offensive message. And yes, my brethren, the Gospel is offensive. Nobody likes being told they're a sinner, not even people who know they're sinners. It is ironic that we're often more offended by what is true about us than what is false. But though that may be the case, we have the responsibility to minimise the offence we cause, even if that means a little personal sacrifice.
My brethren, no cheeseburger will ever be worth as much as a human soul. You'll be lucky to get 90 years out of this life. After that, you get a literal eternity in perfection. Heaven will be better than anything you could experience in this life, and so believe me, you will not be missing out. But the person you are witnessing to, as of yet, does not have Heaven to look forward to. A moment of liberty for you equates to an eternity for them. And obviously, I'm not just referring to food. Any liberty is worth foregoing. Tattoos? Sure, you're allowed to get them, but if you're considering doing so, consider the location. Make sure it's somewhere you can cover it whenever you want. And you're free to wear what you want, but perhaps your clothing sends a bad message to a potential convert. Pay attention to what you wear. Sometimes, even a careless gesture can offend someone. "Obscene" gestures seem almost arbitrary. If you so much as count to two on one hand, you may end up "flipping the bird" to a British person.
Sadly, we live in a world where if you drop a coin on the street, it will be picked up by someone who is offended by your customs. Yet, as Christians, we carry a message that literally alters one's eternal destiny. It is essential that, so far as it depends on us, we are as inoffensive as humanly possible. Do everything short of sin to win the lost to Christ, because if we do not win them, they are the ultimate losers. Let's not lose a soul to Hell over a bacon strip.