The dragon symbol pre-dates Christianity in Wales. Also, there is some controversy over the translation of that parcicular passage of the Bible. One must remember that King James Version was written at a time when the Welsh people were seen as an enemy, and thus what would have been more accurately translated as "The Geat Beast" was given the form of a dragon.

The Red Dragon in Welsh culture has a different significance than the red dragon in Judeo-Christian belief. Here is an interesting explanation: The Welsh flag has two equal horizontal stripes, white above green, and a large red dragon passant. The dragon standard was perhaps first seen in Britain in the shape of the "draco" a standard carried by the cohorts of the Roman legion. The Romans appear to have been inspired by the dragon standard carried by their Dacian and Parthian enemies and had adopted this device by the third century. Carl Lofmark (see below) argues that the dragon of the cohort was more familiar to the British than was the eagle standard of the legions. As Roman legions withdrew at the end of the fourth century and the British were left alone to face Saxon attacks, the dragon would have been a natural symbol for those who wished to preserve their Romanised way of life against the barbarian invader. The ancient poets Aneirin and Taliesin use the Welsh word for dragon "draig" in the sense of "warrior" or "leader" and this usage remained to the Middle Ages. In the Historia Brittonum (ascribed to Nennius) of around 800 A.D. the dragon is seen as a symbol of national independence in the story of the red dragon battling with the white dragon of the Saxon enemy. At the time of the Norman invasion of England in 1066, the dragon symbol seems to have been used by both sides. The Bayeux tapestry shows king Harold close to a dragon standard as he falls and the dragon also appears on the pennant of one of duke William's messengers. (There is a drawing of this on our page about pedigrees and coats of arms in Wales.) Despite its occasional use by other figures famous in Welsh history, the red dragon became the symbol of the Welsh nation through its adoption by the Tudor ancestors of king Henry VII. Edmund and Jasper Tudor had a dragon as crest and supporter to the arms granted them by Henry VI. When Henry Tudor faced king Richard III at the battle of Bosworth in 1485 his battle standards numbered three. One of these carried the arms of St. George of England, one the arms of the house of Beaufort and on one was a "Red ffyry dragon peyntid upon white and Grene Sarcenet". It is held that this dragon banner represented Henry Tudor's claim to be a true representative of the ancient kings of Britain and served as his tribute to the Welsh people who had made his victory possible. Several people have written to Data Wales about variations in the way the dragon is rendered. They have noticed several variations on the Web and wonder, not surprisingly, which one is correct. I took up this matter with Rouge Dragon Pursuivant at the College of Arms in London. This gentleman, whose office was created by Henry VII soon after the Battle of Bosworth Field, reminds us that mythical creatures have always been drawn in a variety of styles. It appears that there is no "standard" Welsh dragon, modern renderings must be based on historic precedents but a degree of variation is inevitable. The dragon on the flag must, however, face to the left, be sited centrally and cover equal parts of the white and green panels. http://www.data-wales.co.uk/flag.htm

The answer previously given does not address your question as to the relationship between the red dragon and the devil of Christianity. I think I can help. In the British Isles, prior to the conquest by the Romans, dragons were a sign of both wisdom and strength. Upon the "enlightenment" by the Romans, all signs and inferences to the dragon, or any animal that might be related, were purged. Many stories, such as King George slaying the dragon, were obviously not factual; that particular story and the paintings that followed depict the King crushing the remnents of old pre-Christian beliefs. The choice of words such as snakes, serpents, or dragons very often refer to the ancient religions - pagan, if you will, and therefore considered unholy. The red dragon was the last of the pagan standards carried in the British Isles; Henry V carried it at the Battle of Agincourt. For a long time the English royal arms showed a lion and dragon facing each other. To promote Christianity and to make peace with Scotland, the Tudors replaced the dragon with a unicorn. So, to finally answer your question, YES! And called so for this very reason. The Welsh, brave, stubborn, and never truly conquered, refused to give up the origins of their faith, which are woven into the origins of their being, and their historical beliefs predate Christianity by nearly 2000 years - so you can see why they hold to it, even if most of the country is Christian today. Pagan or, not, the Red Dragon reminds them of their history, as do the flags of most countries. Being unable to conquer them, Rome deemed them pagan heathens, and their Red Dragon became the representation of yet another face of Satan.