Adoration of the Blessed Sacrament

The underlying theme of the Church's Eucharistic teaching is the fact of "Christ's consoling presence in the Blessed Sacrament. His Real Presence in the fullest sense; the substantial presence by which the whole and complete Christ, God and man, is present" (Pope John Paul II, September 29, 1979).

Once this fact of faith is recognized, it is not difficult to see why prayer before the Blessed Sacrament is so efficacious. Indeed it explains why, without a second thought, Catholics have simply referred to the Real Presence as the Blessed Sacrament. It is a Sacrament, or better, it is the one Sacrament which not only confers grace but contains the very source of grace, namely Jesus Christ.
 
The History of Eucharistic Adoration: Development of Doctrine in the Catholic Church