A new blog post at ChinaAdoptTalk does a magnificent job on this topic:
I don't find it theologically sound -- an analogy to adoption is not an adjuration to adopt. And James 1:27 says we should care for widows and orphans -- and there are lots of ways to care for orphans without adopting them. And if we're going to equate care with adoption, then I want churches to start arranging marriages for widows, too! I also worry that the theology of adoption paints adoption as a way to "save" children, which I think is completely corrosive to adopted children's self esteem, dignity, identity. I also worry that when the focus is on saving children, the requirements of ethical adoption weaken for those with an ends-justify-means mentality.