Truth from Probability

For the next two weeks, as mandated by the cruel Scottish task master who is my boss, I am going to be talking with the senior-high kids in our youth group about "Truth".

One approach to this problem addresses a particular truth, that Jesus is the Son of God, and has a mathematical flavor that is very appealing. This is to look at the Messianic prophecies and compute the probability that one person could have fulfilled them all.

There have been some high profile estimates of this number. A fairly common result is one in 10¹⁷⁰.

You can have lots of fun with this number. For example, there are about 10⁷⁹ atoms in our universe. So one in 10¹⁷⁰ is something like successfully finding, given a single chance, a specific atom randomly placed somewhere in universe. And for good measure, doing it again. And to top it off, pick your own name out of a hat containing all the names of the roughly 100 billion (10¹¹) people who ever lived.

Anyway, my question is this.

Suppose we accept as accurate the 10¹⁷⁰ number. Is this meaningful at all?

This is an oversimplification, but what gives me angst in trying to come up with a way to use this "result" is:

• As believers we get great comfort that we can look back at the Messianic prophecies and see how they were fulfilled in Christ. But we already believe in Christ and the inspiration of scripture. So in some sense we should not be "surprised" that Christ fulfilled all the prophecy. Rather we should be concerned if He hadn't.
  
  
• For a non-believer, will this number be convincing of anything? A non-believer might accept that the prophecies were written before the time of Christ, but almost by definition they will not accept the accuracy of the historic account of Jesus. Won't an unbeliever, one who is mathematically literate enough to glimpse the significance of a number like 10¹⁷⁰, merely conclude that it proves the historic account of Jesus was constructed by learned men who knew the prophecies?

It seems to me that the probability argument, while fascinating, is effective only for someone who (a) accepts the biblical details of Christ's life and death; (b) can appreciate the meaning of the number; but (c) does not believe Him to be the Son of God.

Does such a person exist? Or should I say, what is the probability of encountering such a person?