Death and taxes aside, nothing is certain. It isn’t certain there’s no God and no after-life. It isn’t certain that we’ll enjoy the average life expectancy or even that we’ll still be here this time tomorrow. It’s possible that these things are the case. The last two scenarios may even be probable.
This is the best we can do. Statistically and on the basis of the evidence, it’s probable there is no God (or improbable that there is, if you prefer it that way round.) It’s likely, again mathematically and provided other conditions are met, that you’ll live to the average life expectancy age in the Western world (if that’s where you’re reading this.) More people live to that age and beyond than don’t. It doesn’t mean you or I will. It just makes it more likely; statistically probable. On that basis, it’s probable, but not certain, you’ll be here tomorrow.
Reality operates on probabilities. Possibilities are more of a gamble, which is not to say probabilities aren’t, but possibilities are, quite literally, chancier. That just how it is, however we might wish otherwise, however much misguided religious zealots might declare otherwise. Probably.