Having touched on these very matters in a recent sermon, Purifying the Holy Church, I greatly appreciated James White's wise counsel for apologists and evangelists (White is a skilled apologist with Alpha & Omega Ministries).
Bottom-line? If you do not belong within the church, you have zero credibility "out there" and, even more, you are sinning and putting yourself in grave spiritual danger. I agree with White that this is the missing component and weakness to numerous American apologetic and evangelistic groups, which greatly undermines their effectiveness.
(FYI, I tried to get the video to fit this blog, but it wouldn't work. Watch it full screen at YouTube here).