How long does it take someone to decide to follow Christ?

Here’s a brief comment from a Reclaiming the Mission post (found via ekklesia) that I found interesting:

I argue that a conversion of a post-Christendom “pagan,” who has had little to no exposure to the language and story of Christ in Scripture, requires five years of relational immersion before a decision would even make sense. If you do not have this immersion/context, any decision that is made is prone to be a consumerist one. It in essence is a consumerist decision. It is made based on the perceived immediate benefit. It lasts as long as this perceived benefit remains important. It does not lead to discipleship. I believe it takes five years to provide such a context for someone totally foreign to the gospel.

There’s a lot more depth to this quotation (and if you’re interested, hop over to the original post and chime in on the huge discussion there), but I’d like to simply ask the question: based upon your experiences does it take five years before someone totally ignorant of Christianity can make a rational, non-consumeristic decision to follow Christ?

Any other thoughts?