A federal bill to recognize same-sex unions as marriages lacks sufficient religious freedom protections and will undermine the truth about marriage, the United States Conference of Catholic Bishops said Wednesday.

“The Respect for Marriage Act’s rejection of timeless truths about marriage is evident on its face and in its purpose. It would also betray our country’s commitment to the fundamental right of religious liberty,” Cardinal Timothy Dolan of New York and Bishop Robert Barron of Winona-Rochester said in a Nov. 23 letter to members of Congress.

Dolan heads the U.S. bishops’ Committee for Religious Liberty, while Barron heads the bishops’ Committee on Laity, Marriage, Family Life, and Youth.

“This bill is needless and harmful and must be voted down,” the bishops’ letter said. “At the same time, Congress, and our nation as a whole, must resolve to foster a culture where every individual, as a child of God, is treated with respect and compassion.”