While I am far from an ecumenical as a Christian, there is a reason I don't judge differing views too harshly. It stems from my childhood.
I was raised early in my life in the LDS church. As most LDS youth my age did, I aspired to go on a mission, and to serve the church when I grew older. Even as I went to other churches, I still pretty much considered myself Mormon up until the age of about seventeen.
I was about seventeen when I moved to yet another of the many foster homes I had lived in, this one being a very conservative religious family. When we were discussing church as we were getting to know one another, I explained that I was Mormon. My foster mother's response shocked me:
"Well, I hope you know, that's a CULT".
All my life I had known Mormons. There were no strange practices in our Sunday church services. These people were loving, caring individuals who tried to live out their faith to the best of their abilities. There was no "mind control" or stringent set of rules for adherents to the faith (while they DO have the "Word of Wisdom" among their sacred books, it is important to note that, while the admonitions within it contain advice for holy living, they are by no means requirements for practicing Mormons). When I thought of a cult, I thought (as I still think) of a religious sect that exercises strict control over every aspect of its members' lives. The LDS church simply did not fit that bill.
Ironically, in attempting to evangelize me, these well meaning Christians had put up a wall between me and God. All my life I had lived hoping that what I was doing in my attempt to sincerely worship God was "good enough"; now, not only were these people telling me it wasn't, they were, in fact, telling me that my very belonging to the LDS church was evil.
It would be another six months or so before I would come to a saving knowledge of Jesus Christ. But it was six months during which painful lessons were learned, and I can't help but wonder what hard lessons might have been avoided had these people acted in Christian love instead of judging me based on their preconceived notions at the time. I still know many Mormon individuals, and I know that each and every one of them is doing their level best to serve God to the best of their ability. And while there are areas of their doctrine with which I disagree pretty vehemently, it's fair to say that 99% of people in the Mormon church, just as 99% of the people in any other church, are not really heavily steeped in the finer points of LDS doctrine. They are simply trying to do the best they can, to their own understanding, to serve God. And somehow, I believe God will honor that.
So, when I discuss doctrinal disagreements with someone, I'm usually fairly careful to avoid the word "cult" unless it clearly applies. It is a hurtful word, a divisive word, and, in fact, it burns bridges when we as Christians (especially those of us who consider ourselves evangelists) should be BUILDING them.