When talking to anyone of a different opinion, we normally protect ourselves from these foreign ideologies. These ideologies can be politics, religion or anything else we hold dear.
Said this, yesterday I spoke to a Lutheran pastor (http://project05952381.blogspot.com/2010/08/walking-by-lutheran-church.html). We talked a bit about the differences between the Presbyterian and Lutheran practices. We both protected our beliefs against one another although we agreed on basic Christian concepts.
It's weird how undoubtedly Christianity's become heavily divided -- just like Judaism and Islam. The core beliefs are the same, but we all seem to believe what the true secondary beliefs are.
For example, is the Virgin Mary to be worshiped and/or considered holy? Most ironically, is Jesus really an extension (son) of God, 100% man and/or 100% God? Is the Holy Spirit another extension of God or something derived from God? Should musical instruments be played in church during the hymns? Should pastors marry and have children? Can a woman be a pastor and/or lead a ministry? Can anyone be a pastor or should that person study in a seminary (http://project05952381.blogspot.com/2010/09/some-sort-of-ministry-what-now.html)? Well there are many more, but I don't have patience to find out what we claim as true and then list them all.
