Saw this article today on the BBC. Very interesting. One criticism I have is that there is an assumption that on planets where the conditions would allow complex, intelligent life to develop, such life-forms would appear. I don't think this is necessarily the case, though I'm not denying that it could be. However, put in more moderate terms, this article suggests that there are at least 361 other planets in our galaxy alone that could possibly support an intelligent life-form such as ours.
I am still trying to think about the theological ramifications of this possibility. I don't think there is necessarily a direct challenge to Christianity here, but I do think that this dramatically alters how Christians often do apologetics.
One of the major arguments presented in defense of Christianity (or more generally, of Theism) is called the "Fine-Tuning" Argument. Basically, it says that the conditions necessary for life, and specifically intelligent life, to form are very specific and that the universe could not possibly have produced such conditions randomly. Very frequently, this is done in terms of describing the conditions that allow our planet specifically to support such life. The assumption seems to be that we are unique. This research completely shatters that assumption.
This can't be pushed to far. There are still some more universal conditions that would have to be very specific. For instance, gravity must exist in a specific way to allow the universe to continue to expand. However, the number of factors for which we have to explain the "fine-tuning" has been dramatically reduced. All the factors relating the specific nature of a planet that would support life have been shown to occur frequently. Intelligent "fine-tuning" now seems a much less likely hypothesis for most of these factors. So it seems a different kind of apologetic argument is going to be necessary for Christianity.
I have been fairly skeptical of "classical" arguments for Christianity for a while because they are subject to problems like being refuted or rendered irrelevant by new scientific findings like this. I think a much more beneficial strategy is to start by highlighting several major philosophical problems for naturalism. To me, the most pertinent seem to be that naturalism leads to an incoherent absurdity (namely, that we know absolutely nothing and that all our thoughts, beliefs, and communication is an illusion that is utterly meaningless). These absurdities seem to leave us with the conclusion that the "natural" world is not all that reality consists of. Similar philosophical problems can be raised for pantheism, which seems to leave us with a theistic world-view. From there, I think the evidences for the resurrection of Christ can fairly clearly establish Christianity as the most convincing form of theism.
