What is “Corpus Christi”? 
The term “Corpus Christi” is Latin for “Body of Christ”. The Feast we celebrate on Corpus Christi dates back in 1246 when Bishop Robert de Thorote of Liege established it. It was incorporated and extended as a feast to the Universal Church by Pope Urban IV in 1264. That same year, Pope Urban IV asked St. Thomas Aquinas to compose two Offices, which are prayed for this holy day to this present time. We celebrate this feast every year on the first Thursday or Sunday after the feast of the Holy Trinity. [1]

Why is this a holy day? 
The meaning of this feast is the consideration of and devotion to the Real Presence of Christ in the Eucharist. The center of the feast was to be…a popular devotion reflected in hymns and joy. …Today especially has to be filled with acts of faith and of love for Jesus in the Blessed Sacrament [2]
 
Why should we have a great act of faith and love for Corpus Christi? To have great faith and love for the Eucharist is to have great faith and love for whom we believe to be present Body, Blood, Soul and Divinity in the Eucharist, that is Jesus Christ. This feast is an opportunity to quiet our mind and soul and to make ourselves aware again of the great blessing we have in the Eucharist.

We take time to show our love for Christ in the Most Blessed Sacrament because “it was faith in the real presence of Christ in the Holy Eucharist that led to devotion to Jesus in the Blessed Sacrament outside of Mass as well.” [3]

We recall all those who have lived and died through the centuries for their belief in the Eucharist.
We remember those first century Christians who, knowing they could be killed, bravely took the Eucharist to other Christians who were sick, dying, or imprisoned, because of their belief. As our great devotion and reverence grew through the centuries, the faithful have paved the way to show reverence, devotion and veneration for the Body and Blood of Christ more publicly.

God In the Streets of New York City
One of the great acts of faith that can be traced from this feast day is processing Christ into the streets and public places in order for all to witness Christ. Many places all over the world will process from the Church to their local town squares and back into the church for Adoration.

Lift the City - a Catholic Eucharistic flash mob
A Eucharistic flash mob in the center of Preston organized by the Capuchin Franciscans on Ascension Thursday 2011. What are the responses of the people and what do they tell us about our own response to Christ? Notice the children, their humility, and their joy.
 
What else can we do to show our charity and faith on Corpus Christi? We can go to Mass as the Apostles did for the Passover. When we arrive in the Church, we can genuflect with full reverence to Christ who is present in the tabernacle. If Adoration is offered during the day, we can spend time in prayer with Him for an hour or however long we can stay. Even if there is no Adoration, we can arrive before Mass earlier and/or stay after Mass to pray and just spend time with our Lord.
 
If we do these things, we will be following in the footsteps of many holy people. We will be able to enter into the sufferings and pains of the first martyrs, and we will be able to experience the great happiness that Christ brings to all. More importantly, we will be following Christ, who brings about everlasting joy and freedom from our sins.

Adore him reverently and devoutly; renew in his presence the sincere offerings of your love. Don’t be afraid to tell him that you love him. Thank him for giving you this daily proof of his tender mercy, and encourage yourself to go to Communion in a spirit of trust. I am awed by this mystery of Love. Here is the Lord seeking to use my heart as a throne, committed never to leave me,           provided I don’t run away. [4]

Let us never run away from Jesus but run towards Him in the Body of Christ.