In the Roman Catholic Church, the 4th Sunday of Lent is called Laetare Sunday, or "Rejoice Sunday."
Pope Benedict XVI explained the meaning of this day in an Angelus message in 2007, saying that it is "in Latin called Laetare Sunday, that is, 'Rejoice,' from the first word of the entrance antiphon in the liturgy of Mass."
He then goes on to say that it is a day to rejoice in the gift of the Eucharist:
The liturgy today invites us to rejoice because Easter, the day of Christ's victory over sin and death, is approaching. But where is the source of Christian joy to be found if not in the Eucharist, which Christ left us as spiritual Food while we are pilgrims on this earth?
Pope Benedict continues his reflection on the Eucharist saying, "The Eucharist nurtures in believers of every epoch that deep joy which makes us one with love and peace and originates from communion with God and with our brothers and sisters."
In reality, every Sunday is a day of joy, when we rejoice in the Eucharist.
However, Laetare Sunday in particular reminds us of that joy, pointing us toward the event that established the gift of the Eucharist, given to us at the Last Supper.
As the Church reminds us to be joyful on the 4th Sunday of Lent, may we recall the beauty and love present in the Eucharist and rejoice in it.