“Today’s world expects much from the church regarding the safeguarding of those fundamental human and spiritual values without which human coexistence will not be better nor bring good to future generations,” Cardinal Giovanni Battista Re, the dean of the college, said in his homily.

He prayed that Mary would intercede, and the Holy Spirit would enlighten the cardinal electors “and help them agree on the pope that our time needs.”

The Mass in St. Peter’s Basilica May 7 was the last public event before 133 cardinals from 71 countries were to enter the Sistine Chapel to elect the 267th pope and Pope Francis’ successor. Only cardinals under the age of 80 were eligible to enter the conclave.

Cardinal Re, 91, presided over the Mass “Pro Eligendo Romano Pontifice” (“for the election of the Roman pontiff”) with some 220 other cardinals, including those who would be entering the conclave that afternoon. The prayers and readings made frequent reference to the need to choose a good pastor.

At the start of the Mass, as the choir sang verses of joy and thanks to the Lord from the Psalms, the cardinals processed up the main aisle of the basilica, wearing red vestments.

They listened as Cardinal Re, who headed the Vatican’s then-Congregation for Bishops and the Pontifical Commission for Latin America from 2000 to 2010, underlined the seriousness of the task before them and the qualities every pope – the successor of St. Peter – must embody.

“We are here to invoke the help of the Holy Spirit, to implore his light and strength,” he said, “so that the pope elected may be he whom the church and humanity need at this difficult and complex and tormented turning point in history.”

“To pray, by invoking the Holy Spirit, is the only right and proper attitude to take as the cardinal electors prepare to undertake an act of the highest human and ecclesial responsibility and to make a choice of exceptional importance,” he said.

“This is a human act for which every personal consideration must be set aside, keeping in mind and heart only the God of Jesus Christ and the good of the church and of humanity,” the cardinal warned.

Jesus gave his disciples a “new” commandment, “that you love one another as I have loved you,” he said; that kind of love is one so great and boundless that it includes laying down one’s life for one’s friends.

All of his Jesus’ disciples must always show his same “authentic love in their behavior and commit themselves to building a new civilization” of love, he said, because “love is the only force capable of changing the world.”

This kind of love can be surprising, he said, like when Jesus humbly washed the feet of the apostles, “without discrimination, and not excluding Judas, who would betray him.”

In fact, the fundamental quality of a shepherd “is love to the point of complete self-giving,” Cardinal Re said.

The pre-conclave Mass and its readings invited the world’s cardinals “to fraternal love, to mutual help and to commitment to ecclesial communion and universal human fraternity,” he said.

The shepherd of the universal church has numerous responsibilities, Cardinal Re said, including fostering communion: “communion of all Christians with Christ; communion of the bishops with the pope; communion of the bishops among themselves”; and a communion “that is entirely directed toward communion among persons, peoples and cultures.”

“This is also a strong call to maintain the unity of the church on the path traced out by Christ to the apostles,” he said. This unity “does not mean uniformity, but a firm and profound communion in diversity provided that full fidelity to the Gospel is always maintained.”

“Let us pray, then, that the Holy Spirit, who in the last hundred years has given us a series of truly holy and great pontiffs, will give us a new pope according to God’s heart for the good of the church and of humanity,” the cardinal said.

“Let us pray that God will grant the church a pope who knows how best to awaken the consciences of all and awaken the moral and spiritual energies in today’s society, characterized by great technological progress but which tends to forget God,” he said.

Cardinal Re reminded the cardinal electors that as they sit praying and voting in the Sistine Chapel, Michelangelo’s “image of Jesus the judge” would be “looming” over them.

In a poem St. John Paul II expressed his hope “that during the hours of voting on this weighty decision,” that image would remind them of “the greatness of the responsibility of placing the ‘supreme keys’ in the correct hands,” he said.

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Some five hours after the opening Mass, the cardinals were to process into the Sistine Chapel, swear an oath to uphold the conclave rules, listen to a final reflection and – if they chose to do so – conduct the first ballot.

The cardinals had been meeting almost daily for two weeks to discuss the practical affairs of the papal transition period, the challenges faced by the church and to consider potential candidates for the papacy.