Bishop David Ricken has a message for the 304,614 members of the Green Bay Catholic Diocese: Voting for pro-choice, pro-marriage equality candidates could "put your own soul in jeopardy."

In a letter to parishioners, the bishop warned against voting for candidates who support "non-negotiables" like access to abortion, euthanasia, embryonic stem cell research, human cloning and same sex marriage.

“A well-formed Christian conscience does not permit one to vote for a political program that contradicts fundamental contents of faith and morals,” Ricken wrote in the letter (PDF). "Some candidates and one party have even chosen some of these as their party’s or their personal political platform. To vote for someone in favor of these positions means that you could be morally ‘complicit’ with these choices which are intrinsically evil. This could put your own soul in jeopardy.”

The letter also criticized a new Health & Human Services Department rule that requires most employers to provide free birth control coverage in their health insurance plans. Churches and other religious institutions are exempt from the rule. However, critics of the so-called contraception mandate claim that requiring Catholic employers to provide health insurance plans to that cover contraception is an infringement on religious liberties.

"These positions are indicators of a broader societal disposition to remove God from the public square and from any relation to society whatever. It is precisely religion and the free exercise thereof which has made this country great in the past," Ricken wrote.

Despite its partisan tone, the letter does not specify whether voters should cast their ballot for Republican or Democratic candidates.

The Johnson amendment in the Internal Revenue Code prohibits tax-exempt 501(c)(3) organizations, including churches, from intervening in political campaigns on behalf of or in opposition to any candidate.

"My letter should not be misunderstood as an endorsement of any political candidate or party. The church does not endorse political candidates or political parties,” Ricken said Saturday during a press conference.