What does it mean to be a Christian in our times in a world come of age, where Christians all over the world have to face the challenge posed by religious pluralism and secular humanism and even the challenge of a so-called religionless Christianity in a postmodern era? Answers to this question can be varied, and all of them point to something more crucial and radical. This basic question is to be approached from an equally radical answer given by Jesus of Nazareth in the Sermon on the Mount (Matt 5:1-7:29), wherein we get the blueprint of an authentic programme of life for all humans. The theological and pastoral study of this major discourse of Jesus highlights the parameters of a responsible and committed life.