Family values

The nuclear family unit as we know it did not exist at the time of Jesus and therefore neither he nor his apostles speak of it in any meaningful term. When Jesus spoke of family he said this:


46While Jesus was still talking to the crowd, his mother and brothers stood outside, wanting to speak to him. 47Someone told him, “Your mother and brothers are standing outside, wanting to speak to you.”
48He replied to him, “Who is my mother, and who are my brothers?” 49Pointing to his disciples, he said, “Here are my mother and my brothers. 50For whoever does the will of my Father in heaven is my brother and sister and mother.”


Matt 12:46-50


Jesus means here that meaning that the community of believers is as deep and as important as the family. All Christians are siblings in very real terms, not just metaphorical ones. For we are all born again in baptism by Father God and Mother Church, and we are all brothers and sisters through Christ. That bond is just as strong, if not stronger, than blood-bonds. A Christian has two families, one in blood, and one in Christ. 


Historically, Christianity has promoted alternative forms of living outside of the family unit in brotherhoods and sisterhoods, such as monasteries. Also, celibacy is put forward as an equally valuable way of life as forming a family.


I do not think that "Christian values" as they are found in Scripture in any way point toward the nuclear family as an ideal. They rather point that spiritual relations to God and other believers are more important than blood relations. If you have social-conservative values and are a Christian, than you have a problem in justifying it with Scripture (which imo, you have to). At the very least you have to admit that there are plenty passages in the New Testament that support other views such as the one formulated above.