Inherent of human condition is the sickness of believing the rest are impostors and heathen, and not ourselves, because nobody recognizes his own mistakes … If one must condemn everyone that misses in a particular point then every mortal would have to be burnt a thousand times. The apostles and Luther himself have been mistaken … If I have taken the word, by any reason, it has been because I think it is grave to kill men, under the pretext that they are mistaken on the interpretation of some point, for we know that even the chosen ones are not exempt from sometimes being wrong.

Letter to Oecolampadius, an hebraist of Basel, as quoted by Francisco Javier González Echeverría, and translated by Otis Towns & Miguel González Ancín in the English "Introduction" at Michael Servetus Rresearch