Your questions are terrible. It makes far more sense to say that it is far more likely that it didn't happen, than that your testimony is true. Therefore, one would err to the side of disbelieving the testimony and thus the supposed 'miracle'. Read 'Of Miracles' (Chapter 10 of Hume's "Enquiries Concerning Human Understanding") and try and formulate a cohesive philosophical account contrary to it that supports the idea that miracles exist.
'vale of soul-making', one must progress through adversity to be at one with God. Such is the argument of Ireneaus (sic?) I believe. Though I find it unconvincing, as it relies upon 'the fall' as fact.
Look up anti-realism and religious inclusivism and the arguments for it, MLG. They are reasonable for a religious believer. I can't be bothered to write them out and explain them clearly.
The arguments being put forward by the majority as 'Christian arguments' are a bit of a joke. I know it's unlikely the general populous will be versed in the writings of Aquinas (I can't say I am either), but he basically plagiarises Aristotle and applies it to Christian thought. It is rather good and almost reasonable, unlike the ridiculous stuff spouted by some claiming to be 'christian arguments'. They may be the arguments of the common Christian, but are not representative of the views of Christian scholars.
The only thing, of which I can be certain, is that I am not certain. This presents a contradiction, but only as certainty in belief is in itself, generally, a contradiction.