Well, for those that pray, I'm assuming they are doing so because THEY believe (or maybe just HOPE) that it enhances their lives in some way. That enhancement might not arrive in the form of a magical God-like intervention occuring - although there are situations I've heard of and experienced myself where in fact that does seem to be the case. For all the logical reasons not to pray, there are many instances that just cannot be explained in current terms of 'what's logical' where prayer seems to have offered some sort of a positive impact.
I think though, that prayer does something more. It offers an affirmation to the one engaging in this activity that they are NOT powerless over their own lives, feelings, hopes dreams, worries. That they can somehow contribute a desire to whomever they pray to and that this desire MATTERS.
In situations where a dear one is suffering, prayer can often be the only solace once can find - offering a sense of contribution and genuine caring for that other person's suffering. Worst case scenario in this situation is this: There are two people suffering. One from physical illness, one from worry about the other. One prays for the other. The one doing the praying is the only one who's suffering is alleviated to any degree at all. End result, one person's suffering was alleviated. Best case scenario: 2 people's suffering were alleviated. This is one of the most intrinsic ways in which we acknowledge that we exist as part of a whole. That we are not merely pointless nor random nor accidental in our existence. This is a very necessary acknowledgment for many of us. It helps us define our humanity.
Now as to the effectiveness of prayer, I firmly believe it does provide immense effect. The greater the faith, the greater the effect. Including one's belief that prayer will NOT help. No matter what the belief, it will be affirmed.
What's really cool is that science is beginning to examine this phenomenae. It's still in it's infancy in terms of being able to provide measurable results, but because it delves into quantum physics and the like, I am quite inept at discussing it at any kind of intelligent, provable manner. This would require a left brain, of which I was apparently short changed at birth. lolll
I will try to find some links to reputable studies that have been or are being conducted that can explain it much better than I could ever hope to.
In my most basic understanding, thought is energy and has a significant impact upon what it is directed towards. This is why prayer is believed to have effect. And by prayer, please let me be clear here. All thought is prayer. Meditation is prayer. Fervent desires are prayer. Anything to which one gives one's focus and invests one's energy into thinking about produces a form of prayer. It does not have to be preceded by "Our father, who art in heaven...." that's just a formality that I personally do without. lollll
This is not a new theory by any means, but the scientific examination of it is. Perhaps somewhat accidentally, science is beginning to bridge the gap between itself and religion.
Movies such as "What the Bleep do We Know" are beginning to surface now, and I expect we'll see alot more of similar types of documentaries, movies etc that delve deeper as more empiracle (sp?) evidence comes to light.
There is much written about this very subject if one is truly interested to learn more, and I'll be happy to research some titles if anyone would like me to.