There are times when it is right and good to sit down and listen to what others think. Such an activity can jog our own thinking, and make us weigh our own beliefs, and sharpen our own apologetic skills - an activity that is never a waste of time. However, there are also times when we must stand up and proclaim the truth, no matter what the outcome. Interfaith dialogue is an evangelistic tool, just like any other. It is also an opportunity to join hands with others who believe in moral behaviour, human rights, the necessity of development, the terrible nature of poverty and starvation, etc., to right some of the wrongs on the planet.
Interfaith dialogue can lead to diplomacy which ends wars.
And although we still hold to the belief that Christianity holds the truth, that doesn't mean we can't respect other people and their right to believe what they choose. We shouldn't shirk from speaking respectfully and peacefully with the pr eachers and theologians of other believers, sharing our thoughts and listening to theirs in equal measure. But before you just go out and do it, be sure to connect with organizations that specialize in interfaith dialogue with the religion in question. It might be a good idea to start picking up some books and examining the history and beliefs of other religions. Many interfaith conferences are on joint approaches to such great problems as poverty, disease and homelessness, against which all humans everywhere ought in battle.