@Beth:
That seems to be a common confusion, possibly stemming from the different meaning that "evidence" has in justice.
In justice, anything that was presented by one side or the other, and was admitted in court, is evidence. It may be inconclusive evidence, or false evidence, but it is nevertheless called evidence.
In logic on the other hand, evidence is something that actually supports or refutes a claim. I.e., you have to have some logically sound way of connecting it to the conclusion. If it doesn't do that, it's not evidence at all.
It's a VERY different meaning of the same word.
To further illustrate the fundamental difference, technically there is no such thing as false evidence in logic. If it's false, or really even not supported as true, you can't by definition have a sound argument (i.e., both valid and the premises are supportable as true) from it to any conclusion whatsoever, hence it's not evidence at all.
Also technically there is not such thing as having evidence but not a proof. If you showed that X => Y and X is true, then you have a proof. If you don't have a proof, you don't have an argument or evidence at all.
You probably mean that you don't have a formal logic kind of proof, where something is either true or false, and there is no room for probabilities somewhere in the middle.
That's ok though. You can just as well go informal logic on its rear, or do an inductive proof, or a bayesian proof if you want to be rigorous about induction. You can even go fuzzy logic (which has states like "very" or "somewhat" in addition to just true or false), if you can pull that off.
None of them is really easier than formal logic, though; they just go by different rules. You'd be surprised how much of what is a fallacy in formal logic, is still the same fallacy or has an obvious equivalent, in informal logic or statistics too. And actually on top of that, both of those have fallacies of their own. So, yeah, actually having a proof or argument but not by formal logic, is actually not much easier. Still, if one of them is the only thing that works on that data, you do what you have to do.
But, still, you need to have some sound argument between the premises and the conclusion, or those premises just aren't evidence at all. They're just irrelevant fluff.
Hope that helps.