I can believe only in love that strikes suddenly
Out of a clear blue sky;
I do not believe in the slow germination of friendship
Or one that asks "why?"

Because our love came savagely, suddenly,
Like an act of war,
I cannot conceive a love that rises gently
And subsides without a scar.

Sarah in Graham Greene's novel The End of the Affair, which Houston Grand Opera presents as a world-premiere opera this month, is based on a beautiful American lady, Catherine, married to Harry Walston, who later became Lord Walston. Greene fell deliriously in love with Catherine Walston and, in the above poem, expressed his sudden cataclysmic experience of meeting her.

It took place in an Irish cottage, rough and simple, in Achill, County Mayo. There were no luxurious appointments, just their lust in the air, right at the beginning of this illicit relationship. The following poem shocks. It is an original and powerful statement of love:

A mattress was spread on a cottage floor
And a door closed on a world, but another door
Opened, and I was far
From the old world sadly known
Where the fruitless seeds were sown,
And they called that virtue and this sin.
Did I ever love God before I knew this place
I rest in now...,
For this is love, and this I love
And even my God is here.

Catherine and Graham had a decades-long attachment that would sustain the author, derail him, send him to heights of attainable joy, and to depths of loss and loneliness. Why was this novelist of world stature, who was constantly seeking to solve the mystery of a God he couldn't see, so obsessed?

Catherine Walston said of Greene that his "misery is as real as an illness." She was right. His despair led him to create characters who had spiritual scars, psychic doubts about their faith, and who were unendingly buffeted about by the harsh world we mere humans are relegated to occupy. We can see this in the author's heroine Sarah and his hero Maurice Bendrix in The End of the Affair.

Graham had become a Catholic convert in 1926 to please his first sweetheart, Vivien, and he recalled his first confession and the sense that the promises he made in the cathedral were as heavy as stones. He often doubted his faith, but what he saw when in Mexico, in 1938, strengthened his belief.

In that journey (and he asked me when I became his biographer to follow in his footsteps to Mexico, as well as to many other countries he was drawn to) he traveled by mule up what seemed like never-ending steep slopes of mountains, his neck stiffening, his head aching, and that overhead Mexican sun brutally beating down. Riding a mule, Greene recalled, is like riding a camel‹the back heaves and strains.

At one point he and his guide lost their way, but at about 7 p.m. they came upon four mud-and-wattle huts, "black and silent in the moonless dark." An old man tended them there. He was on the edge of starvation, living with rats, yet he welcomed these strangers without a word about payment and gossiped gently in the dark with them. "I felt myself," said Greene most movingly to me, "back with the population of heaven."

But in Tabasco, the Mexican government was cruel and viciously anti-Catholic, and the author witnessed the burning of churches, the desecration of altars, and the persecution and hanging of priests. In churches where persecution did not exist, Greene was shocked, and certainly moved, to discover peasants who knelt with their arms stretched out in the attitude of the cross, or to see a woman dragging herself up the aisle on her knees. How quiet he found religious observances to be when he returned to England.

Greene's quest for faith was continuous: he sometimes believed and sometimes did not. He stopped going to Mass for many years. His doubts at times were strong and on other occasions he recovered his faith. He had a rather odd saying: "I don't believe my unbelief."

Handsome and extremely well mannered, Greene was a strange, brilliant man with light, almost transparent blue eyes not unlike a Siberian husky's. Those eyes, during interviews, would trouble me. Sometimes they gave off a sense of being blind.

In the end, Greene separated from his wife (although as Catholics they were never divorced). But his love for Walston was astonishing. "I can't get you out of my heart," he told her. "You've splintered inside it and surgeons are useless. They say one day I may die of the splinter, but it can't be removed."

Greene, in some of his novels, has characters appeal to God, even if at that point in their stories they don't believe. They are sensitive non-believers yet in their misery they turn to prayer and to God. In the novel (and in the opera) Sarah and her lover Bendrix are together during an air raid in London at the time of the Second World War. Raids came every evening and Londoners, living like the Morlocks in H.G. Wells's The Time Machine, each night went underground to public shelters.

The raids caused nightly damage. Every civilian would wait for the engine to cut out. Then the bomb would explode. One raid left London a damaged madhouse. In a single night, on April 16, 1941, 2,000 civilians died and 100,000 homes were destroyed. Sarah records in her diary a fateful attack of V1 missiles on June 17, 1944. Bendrix, she writes, goes downstairs to see what has transpired:

He hadn't been gone two minutes when there was an explosion in the street... I knew he was at the front of the house when the bomb fell. I went down the stairs: they were cluttered with rubbish and broken banisters, and the hall was in an awful mess. I didn't see Maurice at first, and then I saw his arm coming out from under the door. I touched his hand: I could have sworn it was a dead hand...and wouldn't I have recognized life if there was any of it left in touching his hand? I knew that if I took his hand and pulled it towards me, it would come away, all by itself, from underneath the door.

Sarah kneels on the floor and prays. With her head resting on the bed, she says, "Dear God...make me believe. I can't believe. Make me." As she further recalls in the diary:

I said, I'm a bitch and a fake and I hate myself. I can't do anything of myself. Make me believe. I shut my eyes tight, and I pressed my nails into the palms of my hands until I could feel nothing but the pain, and I said, I will believe. Let him be alive, and I will believe... I said I love him and I'll do anything if you'll make him alive. I said very slowly, I'll give him up forever, only let him be alive with a chance, and I pressed and pressed and I could feel the skin break, and I said, People can love without seeing each other, can't they, they love You all their lives without seeing You, and then he came in at the door, and he was alive, and I thought now the agony of being without him starts.

It's odd but Greene, in a number of his greatest novels and in one play, tries out variants of this gamble with God. Its origin was an actual and vivid dream, which troubled Greene greatly. In his dream, he saw a little child dying and he offered God his own life in order to save that child. Whether or not what Greene does in his novels and in his dream life would stand the test of theologians, I do not know, but it unfalteringly speaks to the hearts of romantics. In The End of the Affair (a book Greene once called, in a letter to Catherine Walston, "that novel of ominous title"), we see that, although her lover lives, Sarah feels the necessity to keep her end of the bargain, bewildering the one she loves, who has no idea of the price that she has had to pay.

Norman Sherry is the O. R. and Eva Mitchell Distinguished Professor of Literature at Trinity University in San Antonio. The final volume in his three-part work, A Life of Graham Greene, will be released later this year to mark the 100th anniversary of Greene's birth.