Language is always adequate to express anything. The real issue is whether the mind can conceive something. If you can think it, you can designate any sign to represent it. In principle, you can use “X” to represent the contents of an entire book. There is nothing inherently contradictory or impossible about this.
It follows that language itself is adequate to say anything about God – I am sure that God can verbalize anything about himself. Again, “X” is language, and it can represent any thought, so the limitation is in one’s mind, not in language itself. I do not say that we can know or think everything about God. Since he is infinite, there is always more to know or to think about him that we do not already know or think about him. But whatever we can know or think about him, we can say about him.
As for positive and negative language about God, there are those who insist that at least some things about God can be expressed only in negative language. This is not true. I can easily turn into positive language anything that is said about God in negative language.
For example, R. C. Sproul once said that to say that God is “immutable” is negative language, that since we are human, we know only what “mutable” means, and that God is not “mutable,” so that it is impossible to express this divine attribute in positive language. This was awfully careless of him – what about saying, “God always stays the same“? That is positive language, and we know what it means.
Some people think that it sounds more pious or reverent to say that we cannot talk about God in positive terms, but this is both biblically and philosophically false and unnecessary.