I'm going to commence my defence with a quote by Scott Fitzgerald:
The test of a first-rate intelligence is the ability to hold two opposing ideas in mind at the same time and still retain the ability to function.
With that quote, not only can I justify contradicting myself but I can also prove my intelligence to be first-rate! (Thanks, Scott Fitzgerald, I owe you one.)
I've always been uncomfortable with the atheistic position that a lack of evidence of God's existence is sufficient reason to stop praying. I think that argument is a non sequitur. I argued that point earlier with the example of imaginary numbers, because humanity has achieved useful results by working with something that doesn't exist!
Let me now talk about how faith has helped me in my own life, even though I'm an unabashed agnostic.
On three occasions so far, I have suffered excruciatingly painful back spasms. These have been so traumatic that the dates have been burned into my memory: 30 Aug 2001, 27 July 2002, 31 Jan 2007.
I have never before or since experienced such pain. Every time I had a spasm, it seemed as if my back was on fire, and I could not keep myself from screaming. I used to suffer more than one spasm during the first couple of days of each episode, and it was only with the passage of time (and lots of painkillers) that the inflammation eased and the spasms stopped. (It's also chiropractic that has given me what I think is a more permanent solution, but that's another story.)
The specific situation I want to talk about concerns me lying on my side in bed during one of these episodes when a spasm has laid me low. As long as I'm lying still, there is no problem, but I've been lying on my side for a long time, and I'm getting tired. I want to roll over onto my back, but I'm deadly scared that the movement will trigger another spasm. The memory of that excruciating, burning pain paralyses me. I want to turn over, and it's such a simple movement, but I dare not.
How does science or rationalism help me now? They do nothing for me. If I apply my scientific mind to the problem, I cannot rule out the possibility of a spasm with 100% confidence. Even a low probability is to be dreaded, and I cannot bring myself to take the chance and roll over. So I just lie there, paralysed by fear.
Long moments pass. And you know what happens next. There are no atheists in foxholes or with back spasms, and I pray. I pray fervently to any deity I can think of. (Hinduism provides a rich variety ;-). I pray and pray. I rage. I weep.
Ultimately, calm descends on me. A feeling of peace, and a conviction that my fervent prayer will be answered. Note that this is a completely irrational feeling. I have no evidence at all that a deity has heard my prayers or that such a deity even exists. But I need that faith.
And armed with that faith, I turn. And nothing happens. Moments pass, and there is no spasm. I say a prayer of thanks. To the same deity. Who may or may not exist.
After the fact, the incident is easy to analyse and explain. Faith caused my muscles to relax. Relaxed muscles do not go into spasm. That's the scientific explanation, and there is no need to invoke a deity of any sort to explain this phenomenon.
But here's the catch-22. If there's no deity, then where can the faith come from? Rationalism cannot produce the relaxation required, because rationalism stubbornly insists that there is always a finite probability of a spasm occurring. Only faith can assert with absolute certainty that a spasm will not occur. And faith then proceeds to prove its point.
The other area in my life where faith has helped is in dealing with stress, especially at work. I went through a particularly bad phase in a previous job where a particular individual used to give me a lot of stress. My solution was to sit in my car for a few minutes before entering the office and put myself in a state of mind (through prayer) that told me with absolute confidence that my problems would be taken care of. Again, there was no rational reason for arriving at this level of confidence. It was entirely possible that my professional reputation would be damaged and I would be out of a job as a result of the conflict. Faith, however, is self-standing and doesn't require reasoning to back it up. And it worked. I remained calm at work, and nothing catastrophic happened. Pure rationalism would not have helped me control my stress as simply and effectively.
Analysing the situation after the fact, perhaps my calmness was itself a major contributor to the solution. Keeping calm and not reacting to provocation helped to defuse many potentially explosive situations. And being level-headed in a crisis always helped me make better decisions. That's probably what helped me maintain my professional reputation and make a success of what I was working at. But I needed faith to kickstart all of that.
Now this will sound ungrateful on my part, but none of these positive experiences with prayer and faith has caused me to become a 'believer' in the whole spiritual/religious shebang. I'm still fairly convinced that there is no such thing as a soul (no evidence, after all), and that therefore there are no such things as an afterlife, heaven, hell, reincarnation or karma.
But still, why would an agnostic throw away a perfectly useful tool without an adequate substitute? Agnostics are nothing if not practical. And this is why I can hold two opposing ideas in my mind at the same time and still retain the ability to function. Indeed, I need both sets of ideas to function. I don't consider faith to be the enemy of reason or the opposite of reason. Faith is the dual of reason. Each solves a different set of problems.