“A man is not a Jew if he is only one outwardly, … No, a man is a Jew if he is one inwardly.” Romans 2:28
Just substitute “Christian” for “Jew” in the verse. It is what’s inside that counts. We are to live inside out.

For forty years I led you through the desert … yet your sandals did not wear out." Duet. 29:5
“A man is not a Jew if he is only one outwardly, … No, a man is a Jew if he is one inwardly.” Romans 2:28
Just substitute “Christian” for “Jew” in the verse. It is what’s inside that counts. We are to live inside out.