The controversy over recognition of same-sex unions as marriages is a very important part of a larger debate about the definition of a family . While few societies have recognized same-sex unions as marriages , the historical and anthropological record reveals a large range of attitudes towards same-sex unions ranging from praise , to sympathetic toleration , to indifference , to prohibition . Opponents of same-sex marriages have argued that recognition of same-sex marriages would erode religious freedoms , and that same-sex marriage , while doing good for the couples that participate in them and the children they are raising , undermines a right of children to be raised by their biological mother and father .