The characteristic most fully shared by the religions of the world is their incompatibility with each other.
This reality cannot be underestimated in our floppy-thinking American culture. It is overly common for people to think that the “enlightened” religions view all religious views as the same, or at the least, as aiming at the same god. The corrective to this view is that there is no religion, when allowed to speak for itself, that thinks this is the case. Only in the watered-down Americanized versions of Buddhism, Hinduism, Zen and Christianity, do religions view all as one. Without fault, a genuine Buddhist will tell you that you need to follow the teachings of Buddha in order to be enlightened. Confucius and Jesus are not enough.
That is to say, the question of religious unity depends not upon practice but upon teaching, or (expressed more accurately) it depends upon the teaching which gives the practice its meaning; but the teachings are the focal center of disharmony among the world’s religions.
This point is especially poignant given some of the trends in contemporary evangelicalism. It has become trendy to say that what makes a Christian community genuinely Christian is its practices. Montgomery is right on the nose here when he argues that what differentiates religions are their teachings and that it is their teachings which lend value to their practices. Every religious community imaginable can be a wonderful place to be as a result of all kinds of great and loving practices. But that avoids the crucial issue of which ones are wrong about ultimate reality and salvation.
There is a lot more in the post listed above-it should provoke a lot of thought!