Right after the Psalm 100 debacle at UNC I was talking to my college pastor's wife (check out her blog!) about how Christians differ in their views on homosexuality and other "fringe" issues (homosexuality, abortion, birth control, females in ministry, etc.). She said something super insightful (that was actually something her husband had said) that has stuck with me ever since: "fringe" issues aren't really "fringe" issues because they reveal what we think about God and his Word - they're really more like core issues.
For the sake of this discussion, "fringe" issues should be thought of as intrinsically on the "fringe" of Christian doctrine. The issues themselves are not inherently problematic to doctrines such as salvation, and are therefore thought of as unimportant, treated with apathy, or brushed over in order to minimize differences in the church at large.
In some ways, I think exchanging thoughts, ideas, and opinions with believers whose beliefs differ from yours on such issues is helpful and insightful. After all, God created each individual different, each in his image, each to express a different facet of his character in some way. I personally have benefited from friendships with believers who were on the opposite end of the theological spectrum on a number of issues. And, to be perfectly honest, the definitive answer to fringe questions is often not clearly marked in the Bible. In such instances, believers ought to interpret the issue through the lens of the Gospel, scripture as a whole, and God's character.
In Knowledge of the Holy, A.W. Tozer said "What comes into our minds when we think about God is the most important thing about us."
Just take that in for a minute. What you think about God is the most important thing about you. Why? Because how you think about God determines how you act towards and interact with God and others. In terms of "fringe" issues, Christians often deviate from a biblical, gospel-centered worldview (note: not a "Christian" or "right-winged" worldview) when they deviate from God's word and his character. Their thoughts about his character are severely skewed, thus mangling their opinion on issues that, in their minds, don't matter.
Don't get me wrong, your opinion on homosexuality isn't crucial to securing your salvation. By far the most important issue Christians need to have a strong, unwavering opinion on is the Gospel.
But when it comes to other issues, don't look to a political ideology or even another Christian's view on the subject, look to "core" things like scripture and God's character, and make a gospel-centered decision, giving grace to others who disagree with you.