Chief Justice John Roberts and Justices Stephen Breyer, Elena Kagan, Antonin Scalia and Clarence Thomas attended the annual red mass Sunday at Cathedral of St. Matthew the Apostle in Washington, where the congregation traditionally prays for the Supreme Court and government officials.
The mass -- whose name comes from the red vestments traditionally worn in symbolism of the Holy Spirit "tongues of fire" the New Testament says descended on Jesus' apostles at Pentecost -- was also attended by members of Congress and White House Chief of Staff Denis McDonough.
The homily by Dallas Bishop Kevin Farrell, delivered amid the federal government shutdown, stressed that debate requires respect for the other side in every argument, no matter what the disagreement.
"If honest and respectful dialogue means anything, it means that we need to strike a balance in our words and rhetoric so that conviction should never become stridency and saying things with commitment should never become caricaturing anyone else's positions or beliefs," Farrell said.
"E pluribus unum means just that," Farrell said. "It does not mean one size fits all. And it does not mean 'I Did It My Way' has replaced the national anthem."
The Supreme Court's new term, which by statute begins the first Monday in October, will take up for the first time in 30 years the constitutionality of starting government meetings with a prayer when the message is almost exclusively Christian.
The town of Greece, N.Y., near Rochester, wants the court to uphold its practice of opening town council meetings with a prayer.
Two women -- one Jewish and the other atheist -- had sued, claiming the practice amounted to government endorsement of a single faith.
"I don't think you should have to endure religious indoctrination in order to participate in your own town government," Linda Stephens, one of the challengers, told NBC News.
But Town Supervisor John Auberger told the network the practice is an established ritual, dating from the republic's earliest days.
"We have a rich tradition, back to our founding fathers, of opening legislative meetings with a prayer," he said.
An appeals court ruled the invocations violated the First Amendment because they were almost always Christian.
The Supreme Court ruled in 1983 the Nebraska state Legislature could constitutionally open its sessions with a prayer from a Presbyterian minister who was the paid, official chaplain.
But the court has also held in other cases governments cannot appear to endorse a particular religious point of view.