Gustavo Gutiérrez gave the movement its name with his 1971 book, "A Theology of Liberation". In this book, Gutiérrez combined populist ideas with the social teachings of the Catholic Church. He was influenced by an existing socialist current in the Church which included organizations such as the Catholic Worker Movement and the "Jeunesse Ouvrière Chrétienne", a Belgian Christian youth worker organization. He was also influenced by Paul Gauthier's "Christ, the church and the poor" (1965). Gutiérrez's book is based on an understanding of history in which the human being is seen as assuming conscious responsibility for human destiny, and yet Christ the Saviour liberates the human race from sin, which is the root of all disruption of friendship and of all injustice and oppression. Gutiérrez also popularized the phrase "preferential option for the poor", which became a slogan of liberation theology and later appeared in addresses of the Pope. Drawing from the biblical motif on the poor, Gutiérrez asserts that God is revealed as having a preference for those people who are “insignificant", "marginalized", “unimportant", "needy", "despised", and "defenseless". Moreover, he makes clear that terminology of "the poor" in the Christian Bible has social and economic connotations that etymologically go back to the Greek word "ptōchos". To be sure, as to not misinterpret Gutiérrez's definition of the term "preferential option", he stresses, "Preference implies the universality of God’s love, which excludes no one. It is only within the framework of this universality that we can understand the preference, that is, 'what comes first'."