Known simply as Mother Teresa, Saint Teresa of Calcutta was born in Macedonia to an Albanian businessman father and deeply religious mother. As a Loreto nun teaching school in India in 1946, after what she described as a "call within a call" to serve Jesus Christ by serving the poor, Teresa instituted the Missionaries of Charity and dedicated herself entirely to serving the poorest of the poor in Calcutta. Her example and leadership would spread throughout the globe. After years of suffering, Teresa died on September 5, 1997. She was canonized in the Catholic Church by Pope Francis on September 4, 2016. This book proposes that Teresa, through God's divine intervention, originated a distinctive form of theological knowledge that the author names Christo-ecclesio-humano-centric mysticism, defined as a mystical theology demonstrated, in theory and practice, in both seeing Jesus Christ and serving Jesus Christ in the poorest of the poor. God's gift to Teresa of this experiential knowledge of Christ's presence in today's world is shown to be a significant source of theological and pastoral renewal in the Church of the twenty-first century.