Throughout his writings, he consistently strikes a balance between overly personal, pietistic religion on one hand and often hypocritical, external religiosity on the other. Readers of the New Testament will see clearly a call to a radical, personal faith as well as a bold, public witness. I believe that if he were here today, he would reject both the claim that religion should be private and personal (the "naked public square" argument much of Europe has embraced), as well as the idea that we can impose faith from the top down. Based on the full range of his writings, and his example in the book of Acts, I believe Paul would vocally defend the concept of an "open public square" - the idea of freedom OF religion, not freedom from religion - and that he would firmly hold to his belief that the light of truth would speak louder and shine brighter than the darkness of deception.
But Paul also understood something about motivation.
He understood that even Spirit-filled men and women needed encouragement to step into that public square. In his day, there were very few "open public squares" indeed (his experience in Athens was certainly not the norm for him). Believers in many parts of the Roman Empire took a great risk when they shared their faith in any form - whether they simply made their faith known as the motivation for their actions, or responded when asked about the hope that was in them, or boldly preached or taught in a public setting. So Paul, writing to one man known for his faith, laid out a principle that could motivate someone who might otherwise find himself staying silent.
Simply put: The more we share our faith, the more we come to understand just what we have in Christ. As any teacher knows, the best way to cement a lesson is to teach it to someone else. Passing on our faith becomes the divinely-appointed means of strengthening that same faith. In fact, Paul says it's the only way we'll obtain a full understanding of all the good things association with our relationship to Christ. All the Bible study in the world (as crucial as that is!) will not yield the depth of understanding that we will gain from communicating our faith to someone else.
So how, in the still-open public squares in the US and a precious few other countries, or in the naked public squares of Europe, or in the hostile public squares of some parts of the world, can we do this? What should be our relationship to the cultures in which we find ourselves?
Much has been written about Christianity and Culture, but I believe the answer is a simple Biblical principle that transcends all cultural forms: Engage in love.
We are always going to have a fleshly tendency toward fear of man which causes us to either attack or withdraw (fight or flight). When we attack, we create an "us against them" mentality. This mentality does not advance the kingdom of God; if you need proof just look at the Crusades, a horrible mark against the church that mingled selfish motivations with fearful ones and has resulted in entire segments of world that are still closed to the Gospel today. Withdrawing doesn't help either. Withdrawal can look like pacifism and result in tolerant relativism ("all religions are the same"), or it can look like isolationism ("let's just hang out with other believers and wait until Jesus comes").
Engaging in love, however, conquers fear (1 John 4:18). It conquers our fear, but it also becomes a tool to conquer their fears as well. Engaging in love reveals the heart of God to others who may have misconceptions about who He really is. Beyond fulfilling the Great Commandments, engaging in love opens the door for us to fulfill the Great Commission.
So how do we engage in love? There are as many answers to that as there are individuals in the world. A great place to start is www.thejustlife.org, where you will learn much about Biblical justice which the site defines as "love made public." One of their key principles, "Start Small, Dream Big", highlights a continuum from compassion, to incarnational action (loving and meeting needs of one person in unique ways), to community justice, to societal change. The common element to all these is that engaging in love is required. We don't get there by staying in our comfortable homes and churches and never taking the risks of love.
Even as we start to engage, we can be sure God will constantly call us to new levels of love and service, of new opportunities to share our faith. Because He wants us to fully understand all the good things that are wrapped up in knowing Jesus. I have a feeling I've barely begun to scratch the surface.