Sunday morning, protestors gathered outside Sacred Heart of Jesus Catholic School.
Kira Hall was holding a sign that said "God loves all people" outside the church.
"I grew up Catholic in a strong Catholic family with six kids, and I'm just deeply, deeply disappointed by the decision of Sacred Heart," she said.
Another protestor said she believes barring the student goes against the teachings of the Bible.
"I have a daughter that goes to school at Sacred Heart," Colleen Scanlan Lyons said. "I've had 16 years of Catholic education, and this just reached the core of my being as completely wrong and against the teachings of Jesus."
Some parents are considering taking a full-page ad out in a local paper to blast the Archdiocese's decision. Others say they might pull their kids from Sacred Heart school.
Inside the church, Father Bill Breslin explained his decision to his congregation. While he didn't want to speak to reporters, he encouraged people to visit his blog to learn about why he decided bar the student.
On his blog, Breslin said, "This past week we implemented a policy that has been the most difficult decision of my life."
Breslin also said he "chose to protect the faith over doing what would have looked like the loving thing to do."
"Our school is a Catholic school, and our teaching on the sanctity of marriage is as clear as a bell," the blog said. "So, the decision I made was based on my conviction that we needed to rest on the side of backing our beliefs and our values. We need to fight for our Catholic values, because here in Boulder it seems no one else is."
The priest said he believes that his church has every right to make these kinds of decisions.
You can read the entire blog at: http://www.fatherbillsblog.com/.
Boulder Pride is also blogging about the situation. You can read the Boulder Pride blog at:
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