As Ireland goes to the polls to vote on whether to legalize same-sex marriage, one Church official warns that the new law could bring yet-unforeseen consequences for future generations.

"The importance of the vote today cannot be underestimated," said Msgr. John Kennedy, an official of the Congregation for the Doctrine of the Faith, in a May 22 email to CNA.

If passed, the Dublin-native said the referendum "would signal a significant alteration in how marriage is understood, appreciated at a societal level and taught to future generations."

More than 3.2 million people throughout the Republic of Ireland are eligible to vote in Friday's national referendum on whether the constitution should be changed to allow same-sex couples to legally marry.

While 18 countries have already legalized same-sex marriage, Ireland would become the first to adopt the law through popular vote, so long as the referendum passes.

"If passed it would mark a sea-change that would, I imagine, be irreversible and have significant consequences," Msgr. Kennedy said. "Not all of these consequences might be appreciated in the present moment but will have to be confronted in the future."

He observed that while political parties and  public figures have vocalized support for the "Yes" campaign for same-sex marriage, many others, particularly private individuals, "have preferred to remain silent on how they might cast their vote."

Coming from a country with a long history of fidelity to the Catholic Church, shaken only in recent decades by scandals among the clergy and religious, the May 22 referendum is significant.  

The proposed amendment to the constitution to allow for same-sex marriage was introduced in January by the Fine Gael-Labour Government. The proposal must be voted on in a referendum before it can become law.  

Friday's referendum comes 22 years after Ireland decriminalized homosexual acts. In 2010, the country enacted the Civil Partnership and Certain Rights and Obligations of Cohabitants Act, which allowed same-sex couples to enter into civil unions.

Despite the consequences such a law could have on future generations, Msgr. Kennedy is confident that the Church's message will withstand the challenges.

"The Church lives within the structures of society," he said, "and will continue to show respect for the individual choices persons might make."

Regardless of the outcome of the referendum, he continued: "The noble and beautiful teaching on sacramental union of a man and woman as taught by Christ the Lord and as designed by God at creation, will remain at the heart of the message that it brings to the world."

"While society continues to change, the beauty and permanence of Christ's teachings will perhaps shine all the more brightly."

Polls throughout the Republic of Ireland were opened from 7am to 10pm local time on May 22. The results will be announced on Saturday.