'External' in the Bible

For a person is not a Jew because of his appearance, nor is circumcision something just external and physical.

And do not be conformed to this world [any longer with its superficial values and customs], but be transformed and progressively changed [as you mature spiritually] by the renewing of your mind [focusing on godly values and ethical attitudes], so that you may prove [for yourselves] what the will of God is, that which is good and acceptable and perfect [in His plan and purpose for you].