She acknowledged the complainants were offended by the advertisement, but found it did not breach the code of ethics or the code for people in advertising, which relates to how people are portrayed in ads.
She confirmed that while it was a contentious issue, advocacy allowed for advertisers to promote their beliefs and opinions.
The advertisement was an invitation to be informed about one person's experience and was offering an information service to those who might share similar beliefs, the decision said.
The authority said there were no grounds to proceed.
The service on April 13 drew backlash on social media and a protest was planned for outside the church, however only one person picketed the service.