Cardinal Robert Sarah reflected on the Real Presence of Christ in the Eucharist and the meaning of the priesthood in a Mass in St. Peter's Basilica Saturday marking his 50th ordination anniversary.

"The priest lives joy in its fullness at Holy Mass, which is the raison d'être of his existence, what gives meaning to his life," Sarah said in his homily at the Altar of the Chair Sept. 29.

"During the daily Mass the priest comes face to face with Jesus Christ and at that precise moment, he is identified, he identified himself with Christ, becoming not only an Alter Christus, another Christ, but he is really Ipse Christus, the same Christ," he said.

The Prefect for the Congregation for Divine Worship and the Discipline of the Sacraments said the inner life of a priest should center around three things: the cross, the Eucharist, and the Virgin Mary.

"According to St. Josemaría Escrivà, the cross of our Lord Jesus Christ is the vital spring of the priest, the pillar on which his priestly existence is built," he said.

Sarah explained that the cross makes possible "the birth of divine life within us" and that the Virgin Mary watches over one's spiritual development as a mother, who "educates us to grow in faith."

"Without the Eucharist we cannot live," he said. "Jesus reveals to us the secret of this heavenly food, that it is His very flesh that becomes nourishment to enable us to live from His own life, in the unheard-of intimacy of friendship with him."

Sarah said that the priesthood is going through "a deep crisis" today, and asked for prayers for all priests.

"The priest -- here is the most magnificent work, the most generous gift that God has given to humanity, the most precious and unprecedented treasure that exists on earth; the Curé of Ars, St. John Mary Vianney was deeply convinced of this," he said.

"In this Eucharist we entrust the Church and all priests to the maternal goodness of the Virgin Mary, our Mother and Mother of the Church," he prayed.

Born in French Guinea in 1945, Sarah was ordained a priest on July 20, 1969 and made a bishop at the age of 34. The Mass at the Altar of the Chair in St. Peter's Basilica was celebrated in honor of two anniversaries for the cardinal this year -- 50 years as a priest and 40 years as a bishop.

"The heart of this celebration is Jesus Christ, the High Heavenly Priest: 'holy, innocent, without blemish, separated from sinners and raised above the heavens,'" Sarah said.

"God amazes with his choices, He is wonderful and surprising in his generosity and in his love for each of us … Listen to how much he repeats to each of us today: 'Before forming you in the womb, I knew you, before you came out into the light, I consecrated you; I have made you a prophet of the nations," he said.

"This is what the Lord was for me: I was born in a humble and poor environment like that of Nazareth and in an animist and pagan culture, and He made me a Christian, a priest and a bishop," the cardinal said. "Through baptism and priestly ordination He transformed me from nothing into his humble servant, into his beloved son."