But if a Christian friend told me that, I will probably pause and ask a few questions to clarify what he meant. I'm cautious and a little nervous when I say it or hear it.
Tony Payne explains this with an example by starting with the following paragraphs:
It's important to say that God is a mystery, as I suggested in my last post, but I can understand why many evangelicals might be a bit nervous about saying it. I'm a bit nervous myself.
The problem lies not in the truth of the assertion, which I think is unarguable, but in the use to which it is put. You see, if we accept that we may know certain things about God clearly and truly, and also that other things about God remain uncertain or a mystery (because they are not revealed to us), the obvious question becomes, “Well, which things do we know truly, and which things uncertainly or not at all?” And what if there is only an extremely small number of things we know truly and a great many things that we should be agnostic about?
I found it very succinct and helpful.
Go over there and read it.