With all due respect for individual religous beliefs and freedoms, the argument to "preserve religious freedom" is a false argument.
Americans have the right to choose any religious belief they wish, and religous institutions have the right to discriminate on membership all they wish. But the adoption and social work is a government licensed activity, and the institution is acting as an agent of the government.
In this context, the institution must act by the rules that the government sets forth. Or they can choose to not engage in the activitity if it offends their beliefs. The government is specifically enjoined by the First Amendment to not establish the beliefs or practices of any religion over its citizens.
Religious Institutions are free to continue to believe as they wish and to preach their beliefs, even if they are intolerent, bigoted, and prejudiced against other groups. That too is their right under the same First Amendment. But they are not free to force others who are not members of their religion to abide by their beliefs.
There is an implicit threat that some will stop providing thier services should the law prevent discrimination. While this may be a temporary inconvience for some, it will be a business opportunity for others - many who charge lower fees for their services as they don't use the activity to support non-adoption related efforts. In my case, the cost was 60% less than the leading religious group offering the same service.
Agencies should not have the right to discriminate in the name of the government, to deny children from loving would-be parents, to increase the costs to the taxpayer, to make choices for would-be adoptee children based on their personal or religious beliefs over and above the standards set by the government that is specifically chartered to represent all citizens of all beliefs.
To do otherwise is both illegal and immoral. Our nation has always eventually recognized that discrimination is harmful to all citizens great and small. In this case it could not be clearer that "Preserving Religious Freedoms" is a false argument and the Commonwealth must rule for the rights of all citizens.