The labyrinth is not a Christian symbol. It has been found carved into rocks by prehistoric people thousands of years ago. But, for it to have been incorporated into a church it must have had a Christian purpose. We know that many pagan traditions made their way into Christianity in its early days and this may be an example of that process of assimilation.
One colourful hypothesis is that the labyrinth derives from superstition and serves as a trap for evil spirits. The labyrinths of Chartres and St-Quentin are placed near to the west door. Demons (and death) were thought to come into a church from the west and as they could only move in straight lines they would get caught in the devious twists of the labyrinth.
Another suggestion is that a labyrinth marks a “well” of earth energy, but this is taking speculation to an extreme.
In the 19th century, Jules Gailhabaud declared that it wasn’t necessary to look too deeply into the matter. The labyrinth was simply a seal placed on the building by the architect-master-mason to show that all the craftsmanship deployed met the highest standards. To accept this as the explanation we would have to see the labyrinth as no more than a fancy logo and, I think, that would be to underestimate it.
The most popular theory about the labyrinths is that they provided a route of symbolic pilgrimage. The faithful would follow the path from the outside to the inside. This may explain why almost all labyrinths are in northern France (there is only one in the south, in Mirepoix in the Ariège), far from the pilgrimage routes towards Rome and Santiago de Compostela. The labyrinth may have served as a symbolic substitute.
To get closer to the significance of the labyrinth it helps to step back and see it
not as a pagan or Christian motif but a symbol of perennial spirituality.
The labyrinth has several notable characteristics as a piece of art applied to reality. It is an ingenious way of cramming the longest possible path into a given space (usually a circle or a square). It is curious how similar a labyrinth is to a schematic map or, the complexities of human brain anatomy and to the intestines.
This path of the labyrinth is highly indirect as if the objective in following it is not to arrive immediately but to meander. Following a labyrinth you have no choice but to slow down and negotiate the reversals of direction (representing the reversals of life) with equanimity. It thus reminds us that the journey is as important as the getting there and that the journey is an opportunity for reflection. As long as you keep to the path you will arrive safely
The labyrinth represents the paradox that we all know where we are going (death, god or paradise, however you want to think of it) but not how you are going to get there.