Marx was the greatest theologian of the 19th century

Marx was the greatest theologian of the 19th century, because he was the most subtle, the most nuanced, and he had the best sense of humor.  (Or perhaps Marx was the second greatest theologian of the 19th century, second only to Hegel - but it's very close, and I'm not sure who ultimately wins.  Nietzsche might be third, but it's a distant third.)

Wittgenstein famously said, "Whereof one cannot speak, thereof one must pass over in silence."  His comrades initially thought that this made him a logical positivist or even an eliminative materialist.  In reality, Wittgenstein was something more like a mystic, who was deeply invested in poetry.  He identified morality with aesthetics, but not to denigrate either - he thought both were deeply important, but that the truths of morality and aesthetics could not be stated clearly but could only be "shown".  This, to me, is evocative of mystics like Meister Eckhart, for whom God was above all human qualities, including the quality of "existence."  

Karl Marx sometimes strikes me, especially in his mature writings, as a theologian who honors God most deeply by mostly passing the name of God over in silence, so as to avoid idolatry.  (His theory of fetishism, too, is a critique of idolatry.)  

But more importantly, there is a third possibility here - that is, a third potential way of dealing/coping with not just God but with all of what Kant would call antinomies - that is, questions which offer only two possible answers, but where both answers inevitably lead to contradictions - questions like "Is the universe spatially finite or infinite?" or "Did the universe have a beginning in time or not?"  For Kant, such questions, tugging at the edges of the categories of the understanding, simply went beyond what humans could rationally ask.  

The first way of dealing with such issues is to simply, boldly, stake a claim about them, like the Merkabah mystic tanna Rabbi Ishmael, to whom is traditionally ascribed the Shi'ur Qomah which will handily tell you, for instance, the distance between God's thighs and his knees, or the length of God's hands, fingers, and toes (His toes are each apparently "ten thousand ten thousands" (or a hundred million) parasangs long, and a parasang is 30,000 of God's cubits, and each of God's cubits is twice the length of the universe, so there you go).  Moses Maimonides considered this a work of heresy, but you have to admire the boldness, the audacity, of so specific a proclamation.

The second potential way of dealing with such issues, is, indeed, in the manner of one who has taken a monastic vow, to "pass over" these concepts "in silence."  About which, there is nothing more to be said - except perhaps for the obvious objection, that in declaring that these things "must" be passed over in silence, one is, in fact, speaking about them.  Every sentence of the Tractatus, so it seems to me, is nothing other than a moral imperative that Wittgenstein is asserting.  Wittgenstein was quite an authoritarian.

But the third way of dealing with such matters is to indeed speak of them - but to speak of them with a sense of humor.  This is the tactic that, I think, Marx mostly employs.  Of course, the danger here is that ironies will multiply endlessly, with ironies piled upon ironies forever - and Hegel pointed out to us that irony was the distinctive, dialectical character of romanticism.  But I think Marx walks this tightrope very carefully and very well, not falling completely into endless irony.