Genesis 17:25-26 KJV
And Ishmael his son was thirteen years old, when he was circumcised in the flesh of his foreskin.
In the selfsame day was Abraham circumcised, and Ishmael his son.
From the beginning of the covenant between Abraham and God it was manifest that there was a difference between those whose only action was in the flesh and those whose covenant was if the heart.
Abraham and Ishmael were both circumcised the same day. Abraham was ninety nine, Ishmael was thirteen. God's covenant was with Abraham so that, though he could require his thirteen-year-old son to be circumcised, he could do nothing about his heart. Abraham could desire his son to walk with God. Abraham could teach his son how to walk with God. But only Ishmael could choose to walk with God.
Abraham's lineage through Isaac so followed their father's steps that circumcision became a cultural tradition among them (though it too was of the flesh and not the heart) which spread into the Christianized Gentile people's.
Ishmael's lineage carried on the custom but had no interest in the covenant.
Within Christianity we can find each of these three motivations for doing the spiritual thing:
· Church attendance
· Prayer over meals
First is the one who observes these out of fellowship with God.
Next is the one who does them because he is expected to.
Then is the one who does them simply because it is family tradition and culture.
I want to do right not because it is expected but because I have a genuine and living fellowship with God.