To what follows, our moderator has already answered the charge of 
arrogance more ably that I could have done so, so I will confine
myself to answering the charge of illogic.
 


This is how everyone in the western intellectual tradition is, or was,
taught to think. It is the fundamental premis "A is not not-A". If a thing
is true then its converse is necessarilly false. Without this basic 
asumption theology and science as we know them are alike impossible. We
should distinguish the strong and weak meanings of the word "believe",
however. The weak sense means I am not sure. "I believe Tom went to 
the library." (but he could have gone to the track). The strong sense
means I am so certain that I use it as a basis of thought. "I believe 
that nature operates according to certain fundamental laws." (despite 
the fact that nature *appears* capricious and unpredictable). Christian
belief is of the strong kind. (Though Christians may well hold beliefs
of the weak kind on any number of theological and ecclesiological 
topics.)
 

Note that these are two separate ideas. Most hold the first view, but the 
majority do not hold the second. Is is again a matter of pure logic that
if Christanity is true, then Hinduism (for example) must necessarilly be
false, insofar as it contradicts or is incompatible with, Christaianity. 
(And, as a matter of *logic*, vice versa.)
 

It is arrogant to claim to know what *anyone* thinks or wants, unless 
they have told you. Christians believe God has told us what he thinks
and wants.


Most Christians do not base their belief on the Bible, but on the living
tradition of the Church established by Christ and guided constantly
by the Holy Spirit. The Bible is simply the written core of that tradition.


If depends what you mean by differing. If I believe Tom is six feet
tall and you believe he weighs 200 pounds, our beliefs differ, but we 
may both be right. If I believe Tom is six feet tall and you beleive
that he is four foot nine, one of us, at least, must be wrong.
 

Thus you believe that there is a single truth but that no human being 
can find it. You assert that anyone who believe that we can find 
absolute truth is mistaken. In short, you believe that anyone who
does not share your belief on this point is wrong. QED.


Here I begin to suspect that your real difficulty is not with the
knowability of truth, but simply with language. Saying that the glass 
is half empty is not a contradiction of the statement that it is half
full: it is the same fact expressed in different words. (The whole
point of this phrase is to illustrate the different ways the pessimist
and the optimist express the *same* fact.)
 
It is, of course, quite true that different people may express the 
same belief in different words. It is also true that they may fail
to understand each other's words as expressions of the same belief
and may argue bitterly and believe that they are miles apart. Great
scisms have occurred in just this way, and much ecumenical work has
been done simply in resolving differences in language which conceal
agreement in belief. This does not mean, in any sense, that all beliefs
are equally valid. Since some of the beliefs people hold contradict
some other beliefs that other people hold, after all obfuscations
of language and culture in the expression of those beliefs have
been stripped away, some of the beliefs that some people hold must,
**necessarilly** be false, and it is neither arrogant nor illogical
to say so. If I believe X and you believe Y we may both be correct, 
but if Y is equivalent to not-X then one of us is wrong and as long
as we hold our respective beliefs, we must each regard the other 
as in error.