In the autumn of 1549, a holy man and his companion began wandering the Satsuma domain of southern Kyushu, preaching the glory of the Sun Buddha Dainichi. The man, who called himself a so (monk), was reported to come from the “Land of Buddha” and exhorted any who would listen to follow Buppo (the Law of the Buddha). If they did, he may have promised, they would attain naisho (enlightenment) and experience raigo (a welcome to the Pure Land by Amidha Buddha and attendant bodhisattvas).

That man was no Buddhist priest, but Francis Xavier (1506-52), the first Catholic missionary — and one of the first Europeans to set foot in Japan. The Jesuit had traveled from Rome, via India (the Land of Buddha), to spread the gospel.

What followed, however, were two years of linguistic and theological chaos as, on the advice of his interpreter — an ill-educated Japanese who converted to Christianity after stowing away on a Portuguese ship — Xavier preached the Word using “equivalent” Buddhist terms.

It wasn’t until 1552, in a debate with Buddhist scholars, that he realized what terrible misunderstandings had arisen. Not only was Dainichi not synonymous with the Christian God, but the Japanese had no concept of an all-powerful creator-god at all. With the backing of his superiors in Goa and Rome, Xavier swiftly purged Buddhist vocabulary from his preaching.

That this purging was urgently needed is clear from a letter written to his Jesuit brothers in India on Sept. 23, 1555, by Padre Baltasar Gago, who arrived in Japan in 1552. He observed: “These [Buddhist] Japanese have a number of words which they use in their sects. For a long time, we preached them the Truth through the meaning of these words. Once I had become aware of them, however, I changed them immediately, because if one wishes to treat the Truth with words of error and lies, they impart the wrong meaning.”

Gago drew up a list of “dangerous words” and “our own words” — Portuguese or Latin — that they should be replaced with. These included: Hotoke/Dios (God); tamashii/anima (soul; the Buddhist word does not distinguish between vegetative, sensile or rational souls); jodo/paraiso (paradise); and jigoku/infierno (hell).

Though Xavier and Gago were clearly deeply concerned, it’s questionable whether these substitutions — and the concepts behind them — were understood by the Japanese at all. In a 1600 text titled “Doctrina,” for example, the four cardinal virtues were taught with the following enigmatic explanation: “Cardeales no virtudes wa yotsu ari. Hitotsu ni wa, Predencia. Futatsu ni wa, Justicia. Mittsu ni wa, Fortaleza. Yotsu ni wa, Temperanca. (There are four cardinal virtues. The first is Prudence. The second is Justice. The third is Fortitude. The fourth is Temperance.)”

Despite the confusion, Christianity spread apace and had some 300,000 converts in Japan by the turn of the 17th century. But this “exclusivist” religion, introduced to a culture with no prior notion of non-believers being condemned souls, also made powerful enemies. Buddhist leaders, using wordplay of their own, spread the notion that the Christian Deus was nothing but a dai-usu (great lie). In 1587, Toyotomi Hideyoshi ordered the expulsion of all Christian missionaries from Japan. Ten years later, persecution began in earnest with the crucifixion of 26 Japanese converts and European pastors in Nagasaki.

There followed decades of fire and sword. Christians went underground, surviving in priestless communities in Kyushu’s rural north. With their teachers gone, memorized, half-alien prayers (orashio) bearing names such as Kerendo (Credo), Sarube Jina (Salve Regina) and Konchirisan (Act of Contrition) became the spiritual mainstay for these kakure krishitan (hidden Christians).

Ironically, though, the very language barrier that prevented the largely peasant converts from understanding Christian doctrines now knit them together and helped Christianity survive — at least outwardly. Kakure communities embarked on a 200-year game of Chinese whispers, orally transmitting texts peppered with words not of their language whose meanings were gradually lost.

In 1991, when a Sophia University researcher visited the last surviving kakure krishitan, in the Goto Islands off Kyushu, she found their prayers were more than 90 percent phonetically perfect. She also realized that not one of the faithful — not even the congregational leaders — knew what they meant.

The kakure krishitan are gone now, and recordings of their prayers can be heard only in small municipal museums. With them have died the words they guarded down the centuries — all save a few. When you ask for pan (bread) at a restaurant or supermarket, you are using what may be Japan’s oldest Western loanword, the Portuguese pao~. Bread was transformed into the body of Christ in the Catholic mass conducted by the missionary priests, but it also had a tangible link to everyday life — and it is this that likely secured the word’s survival. Today, it is one of the few crumbs remaining of a spiritual and linguistic experiment that promised its Japanese believers paraiso but instead took them to infierno and back.