Why can't most Christians make valid points without quoting scripture?

I do NOT reject Christianity or God (so please don't be so presumptious or judgmental to claim that I do; I am simply asking an entirely legitimate question). But you simply cannot make your point by quoting from a book written by humans, copied and interpreted (and misinterpreted) by other humans, and then selectively put together by other humans to fit their own agendas, making it something less than "the Word of God," as those quoting scripture often claim. (See bible scholar Bart Erhman's "Misquoting Jesus" for an explanation of these agendas and why you should not be quoting scripture to make your points). People are more than willing to be convinced of Christian beliefs that they have not already embraced, but they don't appreciate scripture that has already been misinterpreted (either intentionally or non-intentionally) or that you may be misinterpreting yourself. This is an issue with which you need to deal Otherwise you aliente many who would otherwise be drawn to Christianity