This recent post by David Murray has collected a number of excellent posts addressing the question of whether one should take the time to do a PhD. The post is geared towards those who are in that funny DMZ between academia and pastoral ministry, and wondering how they might mesh.
I should also mention that he was kind enough to include one of my former posts about how PhD students are able (or not) to juggle all the other duties of life while enduring the rigours of writing a thesis. You can find that post here.
Please comment and/or ask questions below about any of the above; I might be able to answer some more of your PhD questions not addressed in these posts!