Clergy leaders of different denominations held a press conference Tuesday morning at the Minnesota State Capitol in support of the marriage amendment.
"We have a duty to protect institutions God put on the Earth since the beginning of creation," said Pastor Sergio Amezuca, of the Brooklyn Park Evangelical Free Church.
The group of 40 leaders gathered on the same day their message began airing on television, supporting one deeply held belief that marriage is "a covenant between a man and a woman."
Archbishop John Neinstedt, head of the largest religious denomination in the state, lead the group, saying the amendment is not meant to be either hurtful or discriminatory.
"It is meant to be a positive affirmation of both the beauty, as well as the importance, of this fundamental union for society," he said.
Neinstedt refused to answer questions after the press conference, and supporters have been less publicly active than opponents of the referendum; however, organizers say they are planning to step up efforts leading up to the election.
The ballot question will read: "Shall the Minnesota Constitution be amended to provide that only a union of one man and one woman shall be valid or recognized as a marriage in Minnesota?"
Support for that measure hasn't changed much since January, according to a Public Policy Polling survey released last week, but those opposed continue to close the gap. The survey of more than 800 likely voters found a virtual tie, with 48 percent saying they would support it and 47 percent saying no.
On Tuesday, Minnesotans United for All Families also released a new TV ad that featured a couple who are both Catholic and Republican and say they experienced a change of heart on gay marriage.