In the beginning

I've seen the face of God. It's kept in the nearby church at Taivassalo on a Dutch surplice made in 1510 and quite human for a god.

The tree of the crucifix at the altar was made 700 years ago by a great artist. His or her name is lost and the work was hidden for centuries when the Lutheran reformation swung this way.

The Christ, along whose arms wooden blood drips from wounded wooden hands, is angular, elongated yet entirely human in his expression of agony become its own morphic dulling of sense and senses. He is made of lime wood. He is hung on a cross, that oldest emblem of a tree, made from spruce: a beautifully circular paradigm of the living tree become the symbol of itself. The bosses at the ends of the tree's arms are of oak. These woods are practical considerations for a sculptor.

Lime has a stable nature when seasoned and is soft enough to the chisel and gouge, while being robust enough to hold even delicate carving well. Spruce, as any boatbuilder would also know, grows straight and true - no curves or knots to this cross. And the oak bosses, never warping, possibly even offcuts from other work the sculptor was making, but perfect for this job. Of course the Trinity is echoed in these three woods.

This whole church might have been made of wood, but instead was made of brick and stone. The brick indicates societal and woodland wealth, albeit in the control of a local aristocrat. It was built in the 1430s and what makes it remarkable, as if the artistry of that cross were not enough, are the glowing brightly coloured frescoes, uncovered in 1890 from two hundred and fifty years of Lutheran whitewash. Protestantism brooks no intermediaries between man and god. There is no need of visual prompts to illustrate creation, so long as there is the bible. In the beginning was the word and the word was with god and the word was god. The absolute primacy of logos over the writhing forms of devils, dragons, martyrdoms, resurrections.

But the sheer vibrancy, vitality of these frescoes, the imagination, the fleshing out of creatures never seen, the faith is something that shakes this cynical old unbeliever: here is beauty.

A pelican feeds her children with her own blood - gushing from her wound - like the christ dripping limewood blood: it's a dragonish pelican - the painter never having seen such a bird, sitting in a pine tree. The pine is instantly recognisable, though not slavishly realistic and its lower limbs have at some point been pruned - the depiction is accurate for old woodland practices.

St John himself cradles the lamb, but he is dressed in a camel's skin.

Here is the first depiction anywhere in Finland of musicians - one a woman - who plays some percussion instrument now lost to the orchestra; the other - a man - blows baggy-cheeked into a bagpipe.

There is a man-headed creature in a hood, with a dog's body and a fish tail. From his mouth comes not the word, but a curling snaking vine.

In purgatory there are two sinners on all fours with sticks in their mouths, roped face to face at the neck - when one pulls away from the flames, the other burns more fiercely and pulls back; but for eternity; 580 years so far.

The evidence of a deep knowledge of wood types and their management is everywhere to be seen in the work of the fresco painters - and is as subtle as the work of the artist who made christ on his wooden tree.

Just behind saint Peter with his key the size of a small iron gate is a couple of lop-limbed oaks. Their limbs may have been used to frame smaller parts of wooden building: possibly small supporting beams. They may also have been used as fuel for the brick furnaces that would have made such demands on timber that pollarding and coppicing practices will have been widespread. Manage the trees, make the bricks, build the church to house the wooden christ.

St Christopher carries that same christ child across an invisible river. Round his calves swim fish that the painter would recognise from this very spot - to this day Baltic herring are caught here and remain a strong part of the economy. Christopher's staff is an entire lopped oak, retaining a topknot of leaves, complete with three remaining roots.

Everywhere, covering walls, arches, corbels is a vast flowering of leaf and green as alive as the medieval woodlands once outside, among which, as today, farmers carve their fields. The church writhes with plant life.

That medieval world effectively came to an end in 1650, when it was painted over and a more sombre colourless world began to be spoken of. In principio erat verbum. Except that Latin was banished too. Here, in the medieval church of Taivassalon in the real Finland, with its whitewashed walls and its crucifix banished to an attic, mass was said in the Finnish tongue for the first time ever.

I should relish the word, and I do; but the loss of the timber-and-plant medieval world - that knowledge, existential rather than symbolic (though it worked through its own powerful visual symbolisms) that loss is more than painful. The supremacy of brick, the down rating of wood is the first modernism leading inevitably to our own habitat impoverished times. A straight path to the debased political manipulations of language that the rule of the word, or the Word, if you prefer, made possible.

There can be no intercession between man and the Word. The trees are painted out.