Prayer - grace makes the difference.

Atheists believe that everything came from nothing, that there is no plan or formulation, no intelligence behind the universe; no creator and no God. Deists are practical atheists. There must have been a first cause, they say, but that creator 'God' just wound up the world and let it go like a clockwork toy that keeps on running until the spring winds down. This 'God' takes no concern with how things work out and obviously there is no point in praying to him.

Christians believe that not only is there a God who made the universe, but this God is concerned with the day to day happenings of our world. Moreover, his concern is not just about the great issues of the day - the outcome of the Iraq war or whether or not the hungry of Africa are fed - but also with the minutest detail of our lives. A God who counts our hairs and watches over sparrows is a God who cares.

But... You see it all sounds so illogical, so unbelievable; when you see the detail involved and the huge canvas on which it is painted, how could anyone care what happens in every particular corner?

It's more incredible than that. This weekend I have been at our Church house party and illustration from Chris Kelly brought it home to me just how unreasonable it all is.

Imagine this: in 1999 Tony Blair was the first serving British Prime Minister to father a child for more than 150 years (Lord John Russell had been the last). 10 Downing Street has a pleasingly central location but has never been thought of a nice place to live. The house had been built on fetid, swampy ground, and where there's a swamp there are rats.

There is this saying that wherever you are in Britain you are never more than 20 feet away from a rat - and this is absolutely nothing to do with the occupant of number 11 Downing Street who at the time was Gordon Brown. (In fact at the time because of the relative sizes of their families and the relative size of the apartments, the Blair family lived at number 11 and Brown at number 10. In fact, the saying about how close we live to rats is an urban legend, completely untrue and based on the estimate from 1900 that there were 40 million rats in Britain and 40 million people.

Nevertheless, imagine that one of these rats from the Downing Street sewers managed to climb up the waste pipe and emerge from the toilet bowl in the Blairs' bathroom. This filthy brown rat, smelling of excrement and covered in fleas, makes its way furtively across the Blairs' carpet. Lurking in the shadows as it invades the bedroom, it espies newborn baby Leo's cot. Sniffing the air, it creeps menacingly across the room to the cradle where the baby is sleeping peacefully. There is no-one to disturb it as it jumps up on the crib.

The rat has long, narrow teeth housed in strong jaws which enable it to devour carrion rotting in the sewers. Its dank, malodorous breath stems from its saliva which is a breeding ground for bacteria. The rat's urine, which is continually shed to mark its territory, contains the bacterium Leptospira ictero-haemorrhagiae which is lethal to humans if it not treated soon enough, causing jaundice and internal bleeding.

The fingers and toes of the newborn human are soft and pliable. The bones are cartilaginous and have not yet calcified and will easily come apart. As the rat bites into the baby's toes it is no great feat for him to take them whole. The fingers too provide a small meal for the dirty creature. The baby cries, but Cherie, the experienced mother, knows that you mustn't respond to the baby's first whimper - that way lie endless disturbed nights. But the crying is persistent and becomes screaming and the infant yelps with pain and the blood streams from his gnawed hands and feet. Cherie feels she must go and comfort the child. As she approaches the cot she sees this black, hairy, foul-smelling creature clasped to the neck of he baby. She screams and in rushes a security guard who snatches the animal from the child's neck. Cherie picks up the child and holds him to her breast, but the blood is flowing and won't stop. An ambulance is called; St Thomas' Hospital is the closest. The infant human contains about the same volume of blood as a rabbit; that is to say about 200 cc, less than half a pint. When the ambulance arrives at the emergency room they set up a drip - no easy task on an infant. A tiny tube is inserted into his trachea. Oxygen is started. But he does not move. His eyes have glazed over; his pupils are dilated. The doctors gently compress his chest. The paddles are applied, the electric pulse administered. All to no avail; the child is dead.

Back in 10 Downing Street the security guard holds the distressed animal at arms length with thick, blue rubber gloves awaiting Tony Blair's decision as to what should become of the beast. Will it receive two shots from a soldier's machine gun? Just as we are used to seeing on our televisions as the SAS dispose of a terrorist. Surely that would be too quick and too easy for such a villain. Perhaps it would be beaten with staves until it was a pulp. Perhaps it would be thrown on the fire to be burnt alive. Perhaps the Blairs' other children would be invited to stab it repeatedly while it was pinned down until life was forced out of it. But when Tony Blair returns from the hospital, a cage is produced and the animal is dispatched to the veterinarian.

To be painlessly put down? Well, no, the vet has instructions to clean the animal up, to de-flea it, to treat it with antibiotics and then to groom it and pamper it. For, you see, the Blairs intend to take it into their family. They intend to adopt it, not as a family pet, but to look after it as if it were the son they had lost. It will sleep in the baby's crib, be fed on the baby's food, be pampered as if it were a son.

Fantastic, you say? Of course, it is just a fantasy, but it illustrates what God has done for us. You see, at just the right time, when we were powerless, Christ died for the ungodly. Very rarely will anyone die for a righteous man, though for a good man someone might possibly risk death. But God demonstrates his own love for us in this: while we were still sinners Christ died for us.

There was no goodness in us that would attract him. He did not die for us because we were better than the others or even because we were the best of a bad bunch. All our righteousness was as filthy rags. We had made no movement towards him; we were rebels, we were enemies of God. It is all, all of grace and nothing of ourselves.

We pray because we have been adopted as sons; rats though we were. He loves to listen to our prayers because He regards us as sons. We pray because we would be unnatural children if we refused to speak to our father.