When you add up all of the very special things that are needed for us to actually exist on this planet as living beings, it becomes darn close to statistically impossible (without some like of *ahem* miracle).
...
Or something like the Participatory Anthropic Principle. There is much more evidence that life is highly improbable besides the scarcity of phosphorous (this is the first I’ve heard of it).
Yup—but we may not be the only miracle—there is no limit, last I heard. :-)