Rev. Thomas Tobin, Bishop of the Roman Catholic Diocese of Providence, has said gay marriage “enshrines into civil law immoral activity.”

The Rhode Island General Assembly last year approved a law recognizing gay and lesbian couples with civil unions as a compromise to a gay marriage bill which appeared to be headed to defeat in the Senate. Supporters have said they are planning to reintroduce the legislation this session.

Tobin, who earlier barred gay Catholics from entering a civil union, criticized the effort in an op-ed titled Five Problems with Homosexual “Marriage” published Wednesday in the Rhode Island Catholic.

Gay marriage, Tobin wrote, “isn't about procuring civil rights for beleaguered homosexual persons. … Same-sex marriage legislation is about distorting a venerable institution – not about civil rights.”

“The natural law, the Holy Scriptures and long-standing religious tradition are very consistent in stating that homosexual activity is immoral, an offense to God, a serious sin. The promotion of homosexual marriage is an attempt to rationalize such behavior and to give it the affirmation, the 'blessing' of the state.”

Tobin also called such unions “an ill-advised social experiment” with “unpredicted outcomes” and warned that they would “pose yet another threat to religious liberty.”

The Rev. Gene Dyszlewkski, chair of the Rhode Island Religious Coalition in Support of Marriage Equality, called Tobin's column “divisive and uninformed.”

“These continued attacks on our gay and lesbian brothers and sisters only further perpetuate the notion that some religious leaders are out of touch with members of their faith,” he said in a statement.