Not long ago, I got into an unexpected discussion with some dear friends that ended up in almost a debate...clearly we were coming from different points of view, though we share faith in Christ. The difference surprised me probably most because of our shared faith, but on the other hand, when two people know Jesus Christ, everything else pales. Everything else is secondary, and knowing Him is the thing that really binds us. I don't believe we differ as much as it seemed then, and with more discussion I think the common ground became more evident--though, indeed it matters so little that we unify on every issue other than our faith.
If we don't share the faith, though, I have so much more to say, and it matters so much more...but I will no longer ever start with the peripheral issues with any unbeliever. I've tried that, and it only leads to unresolvable contention. It's like trying to put a band-aid on someone's knee when they tell you they have pancreatic cancer. The cancer will kill, and even if they have a skinned knee, the band-aid will hardly benefit them like killing the cancer.
When I came to Christ, so many issues that were muddy before suddenly became clear to me. The solution to this imperfect world's problems was pretty clearly delineated in the Scriptures, and so the issues themselves became so important to me that their importance tended to frequently come to the forefront in conversation with unbelievers. That was never fruitful, because the focus was far from Christ, far from His love for them, far from the need of their souls. The focus was on something they opposed, and all they ended up seeing was that Christians were people they disagreed with. That was hardly an effective work of an ambassador for Christ.
There are unbelievers who, having known me then, will now pepper their communication with me with political positioning and they will refer to the causes they support that they know I would not. They will send e-mails bashing the more conservative issues, and I expect that they want a fight. They want me to argue the point, and they anticipate that they can trounce me. And they might be able to, these days; I'm not sure that I agree with every conservative political position, and every decision every conservative politician makes, and I'm definitely not as informed as I would need to be to engage in such a discussion. I'm pretty sure there are a lot of conservative causes and politicians I differ with, though the pro-life issue is the one I stick with. Even then, though, an unbeliever will not get me into a contentious discussion of that issue. It will not bear the fruit leading to eternal life.
I realize that some might think that I am not standing firm if I lie down and take the attacks without addressing them, but working from experience and thinking out the usefulness and the priorities, I cannot push those issues. They will not understand the foundation of it unless they know the Cornerstone Himself. If they come to agree with the cause but haven't come to know Christ, their eternity is still in danger and the stand on that one issue is of limited use. When I can, I point to Christ, and occasionally they tolerate that, though more often they don't. The communication lines even with this are tenuous at best, but if I got into argument about the surrounding issues and could no longer communicate at all with them, I would lose the opportunity to share more of Christ.
And so those issues, though important, aren't part of my discussion with unbelievers. They may be a matter for prayer or other action (prayer being the most likely for me these days), but not for contentious discussion. I know Christ, and Him crucified, and I want to use every opportunity to share His love for them rather than to make them align with my ideals on any artificial foundation.