Sign of the cross, everyone. Genuflect. Bow your heads.

If you are a Catholic and a basketball fan, Wednesday is a newly appointed holy day of obligation. And the obligation is to watch basketball. You aren’t worth your rosary unless you tune in to No. 1 Villanova at No. 5 Xavier at 7 p.m. ET.

Check the @Pontifex Twitter feed for TV details.

This, quite frankly, is the biggest Catholic-school basketball game since the miracle of the Rollie and the fishes in the 1985 national championship game: Villanova 66, Georgetown 64. That Final Four in Lexington, Ky., was the apotheosis of Catholic hoops, and the Big East as well. Three of the four teams were from that conference, and three of the four were Catholic schools – St. John’s was the third.

Thirty-one years later, we finally have two Catholic schools meeting as top-five teams again.

View photos Villanova dealt Xavier its first loss of the season on Dec. 31, 2015, in Villanova, Pa. (AP) More

It hasn’t happened since March 29, 1985, when No. 1 Georgetown beat No. 2 St. John’s in that national semifinal – the last of a quartet of colorful clashes between the two power programs. That was Mullin vs. Ewing, Looie vs. Big John, New York vs. D.C.

The Jesuit-led Hoyas and Vincentian Red Storm (Redmen at the time) played four times that season, every one of them as the Nos. 1 and 2 teams in the country. The Johnnies upset top-ranked Georgetown the first time, and then the Hoyas won the next three – once in February, once in early March in the Big East tournament finals, and then in the Final Four.

And then unranked Villanova shocked everyone by taking down the defending national champions.

And then Catholic basketball cloistered itself and took a vow of blandness.

Al McGuire had already taken his incredible charisma to TV. Digger Phelps’ carnation was wilting at Notre Dame. Rollie, Big John and Looie ran out of steam. Carlesimo and Pitino left their respective Catholic Camelots at Seton Hall and Providence. DePaul became a shell of itself.

At many places they were replaced by middling coaches with lesser personalities. There have been occasional moments of glory in the 21st century – Tom Crean and Dwyane Wade taking Marquette to the 2003 Final Four, Saint Joseph’s going 27-0 in the ’04 regular season, John Thompson III and Georgetown’s Final Four in ’07, Jay Wright and Villanova making it in ’09 on a thrilling buzzer-beater – but for the most part Catholic basketball went the way of the Latin mass.

There have been no national titles since ’85 for a Roman-collar school. Or any other private school not named Duke or Syracuse, for that matter. Gradually but inexorably, the secular state institutions with the football revenues exerted more and more control over the sport.

And along the way, conference realignment ripped up the old Big East, leaving the schools that didn’t play FBS football grasping for something to belong to. That’s when what was old became new again, and the Big East reinvented itself as a Catholic-dominated, private-school basketball league.

Old-guard members Villanova, Georgetown, St. John’s, Seton Hall and Providence kept recent arrivals Marquette and DePaul in the fold. Then they added Creighton and Xavier to the mix.

Butler, the lone non-Catholic college but similarly basketball-centric, joined in as well. (Hopefully the Bulldogs don’t mind fish frys and bingo.)

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