I AM right Faith and what's more I can prove it. You won't be raptured on the 10th September or anytime this month.
You can't know what will happen tomorrow. No one can. We can have a high degree of certainty based on scientific law...that the sun will rise tomorrow, for instance. we can even speculate that earth will exist in 200 years. Science gives us a limited degree of certainty but is not infallible.
In this circumstance, what Tangle is asserting is that he can claim with absolute certainty that Faith will not be raptured because the concept of rapture is an unproven phenomenon. Granted, science cannot predict the future, but we can make statements of fact in circumstances for which there is no tangible frame of reference for a particular argument.
If for example, someone claimed they will be turning into a frog on a given date, I can respond with absolute certainty that they will not be turning into a frog on that date or any date for that matter because there is no mechanism that can turn a human into a frog.
While predictability and probability can be leveraged for concepts within the natural world, such as making predictions on the likelihood of someone being eaten by a shark or being struck by lightning, those prediction mechanisms are not required when dealing with metaphysical assertions.