Let's work off the assumption that we all agree that the lost of the world need to be reached with the gospel. It's a good place to start. Christians are called to evangelize. "Go" unto the world, cannot be done from your desk, from inside your church, or even from your computer. You have to go and rub elbows as they say, and put some real work behind reaching people 'where they are at'. If we all sit around waiting for the world to come to us, or to magically appear in our churches one Sunday morning, not only will you be sadly disappointed, you will be living in opposition to God's calling for your life. I for one do not want to be found there.
So how far do we go? What is the line we cannot cross? Do we compromise in order to reach the Lord? Since there is no simple answer, I'll share with you what the Lord has put on my heart, and what scripture gives us as a guideline.
Looking at this most frequently used verse, here's what we do not see; Paul professing his personal liberties in Christ to act in a way that distracts from putting the focus on Jesus and Jesus only just so he can make his point. We do not see Paul defending his eating of meat that has been sacrificed to idols or drinking alcoholic beverages ~ just because it is his Christian liberty to do so. Don't get me wrong. He does defend it, but not for those reasons. What we do see is this: Paul taking his knowledge of scripture, his knowledge of the people he was addressing, and by applying God's grace boldly going to them the way God made him (fallible, poor, with thorn-in-side, weak yet strong, humble etc.), and reaching people by the thousands.
A bit more theologically, when we look at the text here in Corinthians, Paul's context is the spiritual. What Paul is saying is that when the people he is trying to reach are weak, he also would be weak so as not to offend and lose his opportunity, while boldly, yet humbly explaining the truth of the gospel. Though Paul was free from all men, he became a servant to them while boldly, yet humbly explaining the truth of the gospel. When with the Jews (under the law) he become like a Jew, while boldly, yet humbly explaining the truth of the gospel. To those outside the law (the law of the Jews, not the law of the land), he had become like them while boldly, yet humbly explaining the truth of the gospel. The context of what Paul is saying is spiritual, not physical or worldly. All that he is basing his freedom on is the spiritual guidelines of God, not worldly guidelines of those he is trying to reach.
As a matter of fact, Paul does exactly the opposite. Instead of reveling in his liberties, he lays his liberties aside in favor of making no offense to those who may be weaker. Paul says he has the right to drink, eat meat that was offered to idols and more. He and Barnabas had the right to take along with them a believing wife like the other apostles such as Peter did. But they chose not to do these things! Why? Because they did not want to stumble a brother, and wanted to properly represent the gospel they were proselytizing. They always put the gospel, its message, properly representing Jesus and not stumbling a brother, ahead of the defense of their liberties and freedoms in Christ. Others came first.
The context of Paul being 'all things to all men' is in a sense of spiritual understanding: Their understanding of religion and faith, verses the real understanding of grace and faith. How could Paul represent Jesus, if he participated in acts that detracted from his message, or caused others to question his integrity or that made him look like a hypocrite?
A friend recently pointed out that our youth today can smell a hypocrite a mile away. And they can. When I was their age, I could. Let us not be one. Let us not be one ourselves. Let us celebrate our liberty in Jesus not by conforming to the world around us so that we blend right in, in the way we look, the things we do, the music we listen to, the movies we watch and books we read. Let us instead go to our youth and to the lost of this generation with an understanding of who they are, and where they live.
Let us go out shining the light of Jesus, not reflecting the light of the world.