Different people can have similar symptoms for still different diseases. A symptom--assuming it is properly assessed--constitutes a condition for the person in question. If the remedy applied in response to any given symptom happens to be an effective remedy for the underlying disease, then the actual--and ostensible--disease has been addressed. And sometimes the disease just cured is never diagnosed, or is diagnosed incorrectly.
If we humans live in a state of--with the disease of--sin, then what we can experience about our sin is what we can experience as a set of conditions--a set of predilections to sinfulness, a set of predilections that is unique in its relative particulars for each of us. We can say that we have the disease of sin, but we cannot claim to understand that disease. We know nothing more about why we were created with the potential for sin, than we know about why God created evil.
Jesus just assumes that we are sinful, and then he tells us how to address the conditions of sinfulness in our lives. Paul, on the other hand, seems compelled to act as though the underlying disease of sinfulness can be extracted in its explanation from the story of the Garden of Eden. The notion of the "fall" into sinfulness at the eating of the Forbidden Fruit--that sophomoric contention of how persons capable of entertaining blasphemy about God can become "sinful" persons only upon the subsequent eating of a morsel--is put forward by Paul as though a divinely-provided "diagnosis" of our "disease" of sin is present in Genesis. This is not so. We were sinful from the start (or, as I have described about our "shame" in being ever proto-sinful, we have borne the pre-conceptual and pre-verbal shame of sinfulness from the very dawn of our creation.)
The upshot of all of this is simple. We all have conditions that describe our physical states. Those are the things we know about ourselves, and it is only provisionally that we can claim that any of our underlying disease states are known to us. We all have conditions that describe our moral states. Those are the things we know about ourselves, and it is only provisionally that we can claim that our underlying sinful-states are known to us.
