Folau replied to a comment on an Instagram post saying God's plan for gay people is "hell, unless they repent of their sins and turn to God".
Tuiloma Lina Samu says those comments are harmful for people who already deal with intolerance and rejection, based on their sexuality.
"Those words hurt and they hurt significantly especially vulnerable people who are already marginalised people, who are already rejected and ostracized by communities and families," she says.
"What we want to say to this brother is, be careful. Your words they have a lot of weight, especially with you being a well-known person and especially coming from a Christian point of view."