EVERY DAY when I ride BART, I see some of my fellow riders pass the time with their eyes closed, but most passengers are awake, reading or conversing, or knitting, or working, or staring straight ahead.

I'd be remiss, however, in neglecting to mention the few who pray.

One morning, an Orthodox Jew on my right, holding his tefillin (prayer boxes), bowed rhythmically as he prayed while a Christian on my left read scripture on a PalmPilot. I half expected to see a Muslim performing salat in the aisle in front of me, completing the Abrahamic triad.

Last week, as I rode BART home from work in the evening, I looked up from my book to see that everyone around me had their eyes closed. I felt as though I was intruding, as though I'd been given an unexpected intimacy.

We close our eyes in private, when we feel safe. We are tremendously lucky that we live in a civilization that protects us, a society where people in public spaces can sometimes rest their eyes without fear.

I looked at them, trying not to stare, and imagined what might be happening in their heads.

A few of them were napping, perhaps, although sleeping on BART is a most dangerous game. I've inadvertently ended up in Orinda that way.

I'm sure one or two were indulging in fantasy. I only wish I could derive pleasure from that. If I try to have a fun daydream about, say, winning the lottery, I can't help but consider taxes, the administrative logistics of philanthropy, the failings of my current budget, and so on.

The explanation I found most appealing, as I looked around our temporary sanctuary, was quiet prayer. Somehow I found it comforting to imagine my fellow riders meditating or asking God to give them strength and wisdom.

When I was a child, I prayed kneeling toward an altar in the corner of the kitchen, my closed eyes admitting a faint glow from oil lamps and the string of lights surrounding the idols. I prayed for answers to questions that seemed insistent — shall I let myself fall in love with this boy? — but I can barely remember the prayers now, just the physical ritual I performed, lighting incense and making circles of smoke. I found the ritual calming, but only once did my prayers seem to receive an answer: the image of a carousel, whirling and spinning but always returning me to the same spot.

"This too shall pass," the epiphany said. Or perhaps it meant that I was stuck in a rut. Parables and metaphors didn't lend themselves to a 13-year-old's amateurish interpretation.

Now I have little representations of Ganesha, the Hindu god of entryways, opportunities and good luck, scattered about my home, but no real altar. I pray, like so many armchair agnostics, only when I am in crisis.

But at work, when certain songs come on the streamed Internet radio, I feel a certain spiritual urge. Upon hearing "Birdhouse in Your Soul" by They Might Be Giants, or "Hide And Seek" by Imogen Heap, I lean back in my office chair and close my eyes and listen, and the world seems to whirl around me.

I hesitate to call it prayer — what do you call the quiet meditations of a person who swings from believer to atheist to agnostic in a week?

Anyway, it's less prayer than a music-aided reorientation inward. I'm not very disciplined, so I have to close my eyes to ignore the outside world.

To those riders on BART, I was one of those bits of external stimuli that they were trying to ignore. They were closing their eyes, choosing to blind themselves, because the things they could see got in the way of considering the things no one can see.

That's faith.

We make our own cycles, layering routine atop routine. I ride BART. I read my book. I walk home. I turn the key twice. Our habits turn into ruts because we find comfort in pretending our lives are predictable.

And then, every night, I exercise my little faith: I close my eyes, giving myself over to dreams and to darkness.

Sumana Harihareswara writes for Bay Area Living each week. You can write to her at sumana@crummy.com.