Developments in spiritual thought complicated notions of evil in sixteenth-century Spain. As innovations in devotional practice encroached on traditional methods, church authorities began to see them as abhorrent. Teresa's spiritual guides assumed that her supernatural experiences came from the devil, and it was not until she began confessing to Jesuits, who opened a school in Avila in 1554, that priests began taking her seriously. The devil appealed to the senses, stirring up bodily fluids or whispering deleterious thoughts so enticing that it was difficult to discern whether they were good or evil. Teresa saw herself as God's warrior doing battle against evil in the form of violence, hypocrisy, tepidity, jealousy, malevolent or mistaken intentions, and heresy. Echoing the opinions of medieval theologian Jean Gerson, the Franciscan friar Martin de Castanega insisted on women's susceptibility to demons, suggesting that since men are the ones who administer the sacraments, the devil naturally turns to women for adherents.