ROME — Against the backdrop of a contentious Synod of Bishops on the family, Pope Francis found a way on Sunday to remind the 270 prelates gathered in Rome, as well as everyone else, what it’s all about with another papal first: He canonized a married couple who had children.

The French couple are the parents of St. Therese of Lisieux, a 19th-century Discalced Carmelite nun known popularly as the “Little Flower.”

“The holy spouses Louis Martin and Marie-Azélie Guérin practiced Christian service in the family, creating day by day an environment of faith and love which nurtured the vocations of their daughters,” Francis said in his homily on Sunday.

The husband was a watchmaker, his wife a lacemaker. Both once tried to join a religious community, Martin to become a monk and Guérin to become a nun. He was rejected because he didn’t know Latin, and she because of poor health.

They met in 1858, and three months later they were married.

They were celibate during their first year of marriage, trying to recreate the religious life they felt had been denied to them. However, a priest advised them that one of their children could be called to religious life themselves, and eventually they had nine.

The five who survived childhood, all daughters, joined convents. Four of them became Carmelites, and one became a Visitation sister.

The youngest, Marie Francoise Therese, is today known to the world as St. Therese of Lisieux. She was the author of “Story of a Soul,” and is one of only four women who have been declared Doctors of the Church.

“The good God gave me a father and mother more worthy of Heaven than of earth,” is how she once described her parents.

Francis is particularly devoted to Therese, who died at the age of 24 in 1897 and was later honored with the title doctor of the church.

Francis has had a copy of Therese’s “Story of a Soul” on his bookshelf since his days as a novice. As archbishop of Buenos Aires, he had her image on his desk. And he has said that whenever he has a problem, he directs his payers to Santa Teresita, as she is known in Spanish, and often a white rose appears to him as a sign that she has heard his prayers.

In 2015 a canonization cause for another of the couple’s daughters, Leonia Martin, was opened.

It is not insignificant that both miracles required for the canonization concerned the inexplicable cures of newborns born with what doctors determined to be life-ending ailments.

When the Martins were beatified in 2008, the “miracle” concerned little Pietro Shiliro, born in the Italian city Monza in 2002 with a congenital lung deformation that doctors said he could not survive. The priest who was called to baptize him encouraged his parents to pray for the Martins’ intercession. After a month in the ICU, during which he came close to death, he was released and is now a healthy teenager.

The second miracle needed for the Martins’ canonization concerned little Carmen, born at 28 weeks on Oct. 15, 2008 in Valencia, Spain after a difficult pregnancy. Two days later, she suffered a cerebral hemorrhage that caused near-fatal blood poisoning. Her parents went to the Carmelite nuns seeking guidance; they suggested they pray to the intercession of the Martins, who had just been beatified on Oct. 17, 2008 in Lisieux.

After three months in the hospital, Carmen was released, cured, on Jan. 2, 2009 — the 135th anniversary of the birth of the Martins’ youngest daughter, Therese.

On Sunday, Francis also canonized Italian Rev. Vincent Grossi, a late 19th- and early 20th-century figure whom the pontiff defined as a “zealous parish priest, ever attentive to the needs of his people,” and Spaniard Sister Mary of the Immaculate Conception, an early 20th-century nun who devoted her life “to serving the least of our brothers and sisters, especially the children of the poor and the sick.”

In his homily, the pontiff appealed to the synod bishops and the faithful gathered in St. Peter’s Square to follow Jesus “along the path of love and service, and to reject the worldly temptation of seeking the first place and commanding others.”

Material from the Associated Press was used in this report.