The conquerors, and later the missionaries, believed in observing the temples, about the sacred images of the Mexicans, which were signs that in their eyes could not come from any religion other than the Christian crosses. Coming from the closed and exclusive spiritual worlds, they could not imagine a cross having another origin and meaning than that of the Christian cross. For example, the cross of Quetzacoatl on his head was the symbol of the four directions of space, of the four cardinal points, as corresponded to the wind god Quetzacoatl-Ehecatl.
In this way, the crosses of ancient Mexico, very different from each other, were unified and taken to a cross-shaped scheme to be interpreted as the signs of a previous evangelization. When the Spaniards discovered the temple of Ehecatl in Calixtlahuaca, and they saw a magnificent cross that was at the foot of the construction, indeed very similar to the Egyptian cross. The beard with which this God was represented in the middle part of America, made him look European. Quetzalcoatl, that figuratively meant "The Precious Gem", appeared as a synonym of Thome the Greek, which also meant twin, hence the translation of Quetzalcoatl by St Thome or St. Thomas, by this association of ideas, Soon Quetzalcoatl presented its characteristics of Spanish apposite or evangelizer. This was proved by what the Indians said of him:
The initiator of mortification, promoter of the belief of a single god, chaste ascetic, announcer of the Conquest, arranged, pursued and had ended its existence with an ascent to heaven and with a promise of a future restoration of a blessed kingdom. Many similarities with a saint so as not to provoke a passionate question.
St. Thomas had traditionally been an apostle who had preached in the East, far beyond the Ganges River, Marco Polo on his fantastic journey, had reached his grave at Malabar, and had taken a bit of burial ground to Europe. Fraile Diego Durán, in chapter LXXIX of his book History of Indian Women in New Spain, talks about Pre-Evangelization. He was the first to give authority to the idea that Quetzalcoatl was the same Saint Thomas. The idea of the evangelization of the Indians by this apostle was tranquilizing. He solved a great theological problem of the existence of a new world where the word "God" had not reached them. The inner beliefs of the Spaniards would have been shattered if the Bible had lied or omitted America. Quetzalcoatl Santo Tomás, resolved in the first spiritual phase all these doubts and was one of the examples of the mixtures that arose between the cosmological myths of Old Mexico and Christianity.