Did God really use 40 days of rain to "prepare" Noah?

In his book, The Purpose Driven Life, Rick Warren claims that "Whenever God wanted to prepare someone for his purposes, he took 40 days." (This is the rationale behind his "40 days of purpose" program.) By way of example, he cites how God used 40 days of rain to prepare Noah for his divine mission.

Now, I'm pretty sure that the Bible never says that God always uses 40 days to prepare someone spiritually. That is one reason why that I think that Warren's claim is on shaky ground. In addition though, I think that his example with regard to Noah is questionable as well.Did God use 40 days of rain to prepare Noah? I don't believe so, for several reasons:

1. Noah was clearly prepared long before the flood came. God had selected him, out of all of humanity, to build the ark and preserve the human race. This happened at least 120 years before the first drop of rain during those 40 days!
2. Noah and his family were in the ark for 53 weeks -- more than a year! (Genesis 8:14) There were 40 days of rain, but after that, the waters continued to rise, since the fountains of the earth had been opened up. Even after that, it took many more weeks for the waters to subside. It would be rather silly to pick out just 40 days and single this period out as the time of Noah's spiritual preparation.

So, why does this matter? In the grand scheme of things, does this error really affect anyone?

I think it does matter, and here's why. First, we must never claim that the Bible says something when it does not. If we value the truth, then we must never ascribe things to the Bible that it does not say.

Second, this sort of teaching can lead people down wrongful paths. If God is calling someone in a particular direction -- to lead a Bible study, for example, or to volunteer at a local crisis pregnancy center -- I would hate for that person to think that she must first undergo a 40 day training period. Sometimes, this might be prudent, but at other times, we must simply go and obey! Conversely, I would hate for someone to think that God has already "prepared" him or her, simply because the prescribed 40-day period has elapsed. What if that particular person needs more time to be properly equipped?

And third, I think this sets a poor example for how to exegete the Scriptures. Even if Rick Warren's conclusion were correct (which I contest), it would still illustrate a careless and tortuous approach to the Scriptures. Whenever we teach from the Bible, we are not merely proclaiming truths; rather, we are also setting an example in the manner by which we discern these truths. This is not something to be taken lightly.

So in summary, I disagree that God always used 40 days to prepare someone, and I disagree that God used 40 days to prepare Noah. I think that is going beyond what the Scriptures teach, andI think that by doing so, it sets a dangerous precedent.

(I recommend the following link for people who want to read more about the exegetical problems in The Purpose Driven Life. I don't necessarily agree with all the criticisms voiced in that article, but I believe that the gist of it is accurate.)