I am between flights. It’s a four-day wait in this case, and I can spend it at home, so it probably doesn’t constitute a proper layover. But it feels like a layover, and I have a difficult time concentrating on anything but my connecting flight, the one that will unite me with my sister.

I’m headed from one party to another. The first party took place in Chicago last weekend, and featured the wedding of my nephew to a beautiful young woman. That was a real party, complete with laughter, presents, and cake.

The second party, the one that will take place south of San Francisco this weekend, is also impossibly billed as a celebration.

There may be cake, but that’s where the similarities will end. It’s intended to celebrate my sister’s life, a life that will soon be coming to a close. The cancer that started in her breast has now spread throughout her body, an equal-opportunity destroyer with no organ left behind, and she will observe the festivities from her wheelchair during the few hours she’s awake on Saturday. She has a month or two to live.

It’s goodbye. Her friends have called it a party, a celebration, but it doesn’t feel like a party to me. It feels like a wake, with the corpse still propped up in the corner.

But no, not a corpse. My sister. She of the mere 46 years, and the kind, loving husband who has been at her side through almost a decade of hell, and the fifteen year-old daughter. She of the research papers and the tireless work that allows autistic kids to lead more normal lives. She of the tiny hand that curled around my finger when she was a baby.

In the interim, here at this airport lounge I call home, life continues in all its insistent intensity. The plumber showed up at my door this morning at the same time the phone was ringing at the same time I was frantically editing copy for work to meet a 10:00 a.m. deadline.

There were 173 email messages waiting for me in my inbox after returning from Chicago, and at least 50 of them called for an immediate response. There is no lounging in this lounge, no time to collect one’s thoughts and prepare for the next flight. I will walk into the next party utterly unprepared, tongue-tied, at loose ends.

But here is what I will say, I think: I love you. I’ll miss you. They are true words, and wholly inadequate. I would write sonnets if I could, but I have to write marketing brochures and press releases in the meantime.

For as long as I can remember I have been fascinated by the philosophical and theological problem of evil—its continuing existence and God’s apparent inability or unwillingness to eradicate it.

I know the standard Christian answers to the conundrum. We live in a fallen world. God gives us free will, and with that comes the capacity to choose evil. We see through the glass dimly, but eventually we will see face to face. There is much that we don’t know or understand. God will wipe away every tear, love will have the final word, and evil will be swept away.

I believe these things. But I have also seen what happens when individuals are faced with inexplicable tragedy that bears the particular imprint of a life that is loved. C.S. Lewis wrote a fine, closely reasoned treatise called The Problem of Pain that explored each of the Christian responses outlined above.

Then he watched his wife suffer and die from cancer, and set down his thoughts in A Grief Observed, a raw, messy, open wound of a book that posits no answers, offers no explanations, but simply howls with pain and grief.

I like C.S. Lewis the thinker. I like C.S. Lewis the man even more.

I have tried to wrap my head around this for decades. And I have failed. Job suffered greatly, inexplicably, but at least God spoke to him out of the whirlwind and told him to shut up.

In the absence of the whirlwind I yammer on, voicing my complaint. Why? Why only 46 years? Why this woman, who has a family who needs her, and who blesses the lives of those around her, and those far away?

I don’t know. I don’t understand. But I do know that I have been offered the ghastly gift of knowing the future. Sometime in the autumn or early winter of 2011 my sister will die. Knowing that, there are certain words that should and must be said. And I will say them. It is a paltry, ridiculous gift, and in the face of horror and suffering and sorrow it is all I can give. I will get on the plane, and I will travel, and I will be there.

In Chicago last Saturday my nephew embarked on a new life. Just south of San Francisco, my sister will soon do the same. I believe that.

But no one told me in catechism class how the old life can rip your heart out. No one told me that the leap of faith would look something like a broadjump across the Grand Canyon, that the impetus behind the leap is not nearly enough to carry one across the chasm.

In four days I will fly again. I hold on to that, hold on to the reality of one more weekend, the possibility of one more opportunity to let go, to do what I cannot bear by myself.