No possible way to justify Christian belief?

I'm often surprised at the bluntness of many skeptics, particularly those who espouse the problem of evil as an utter disproof of God. I often hear them say "there is no possible argument you could give that would show that a good and loving God could allow such suffering to occur around the world." Or "There is no way Christianity can be reasonable, as it is committed to be based on faith, which is belief without reason." These statements are text book examples of the fallacy known as poisoning the well. And they are yet another way skeptics slither out of any burden of proof, as they are an attempt to discredit any argument made in favor of a position before it is even made.

Now if the skeptic first gave a critique of every argument made by Christians in support of Christianity and then proceeded to state that there is no good reason to believe Christianity then that would be one thing. However, what the skeptic is saying here is not only that there are no good refutation of the problem of evil, but that there could never be any good refutations. This seems to espouse that it is knowable a-priori that God cannot exist while evil exists. So basically the skeptic is asserting a tautology between the two statements; evil exists and God does not exist. But to assert such a tautology without proper justification is tantamount to circular reasoning. Ironically such a strong claim would require a very powerful argument to demonstrate such an argument.