are Christians in spite of their protestations I bet.
You clearly don't understand what "being a Christian" means.
Being a Christian means that:
1. You believe God (the God of Abraham, Isaac, and Jacob, the Creator of the universe) exists.
2. You have a relationship with Him.
- under the New Covenant (not currently accessible), this means that you are part of a priestly nation whose God is the Lord, who (as a nation) believes that Christ is the Messiah.
- under Paul's dispensation of grace (currently accessible to anyone on earth), your relationship with Him is a personal one, your Lord and Savior.
@Clete has a far better breakdown of this, but this is an extremely high level view.
Being a Christian means that these people, who are
even the most avowedly anti-Christian, atheist secularists in your family
who
still hold to many distinctive and signature Christian morals
are by definition NOT Christians.
Which means this:
implicitly iow, Christians, even if they don't appreciate where they inherited their moral sense from.
Is false.
Holding to certain societal values does not make you Christian.
Having a relationship with God through the above dispensations makes you a Christian.
The societal values follow from that relationship. They do not come before it.