I just came across a little book that we read in our Intro. Church History course in seminary. It's The Astonished Heart: Reclaiming the Good News from the Lost-and-Found of Church History by Robert Farrar Capon. It contains one of my favourite quotes. It's actually a whole paragraph so here it is.
To begin with, Christianity is not a religion; it's the proclamation of the end of religion. Religion is a human activity dedicated to the job of reconciling God to humanity and humanity to itself. The Gospel, however—the Good News of our Lord and Savior Jesus Christ—is the astonishing announcement that God has done the whole work of reconciliation without a scrap of human assistance. It is the bizarre proclamation that religion is over, period. All the efforts of the human race to straighten up the mess of history by plausible religious devices—all the chicken sacrifices, all the fasts, all the mysticism, all the moral exhortations, all the threats—have been canceled by God for lack of saving interest. More astonishingly still, their purpose has been fulfilled, once for all and free for nothing, by the totally non-religious death and resurrection of a Galilean nobody. Admittedly, Christians may use the forms of religion—but only because the church is the sign to the world of God's accomplishment of what religion tried (and failed) to do, not because any of the church's devices can actually get the job done. The church, therefore, must always be on its guard against giving the impression that its rites, ceremonies, and requirements have any religious efficacy in and of themselves. All such things are simply sacraments—real presences under particular signs—of the indiscriminate gift of grace that God in Christ has given everybody.