674. Baptism Was Instituted as a Replacement for Circumcision Because Circumcision of the Foreskin Symbolized Circumcision of the Heart; the Intent Was to Create an Internal Church to Replace the External Church, Which as a Whole and in Every Detail Was an Allegory of That Internal Church
It is well known throughout Christianity that we have an inner self and an outer self, that our outer self is the same as our earthly self, and that our inner self is the same as our spiritual self, because it contains our spirit. It is also known that because the church consists of human beings, there is such a thing as a church that is internal in nature and such a thing as a church that is external in nature.
If we conduct research on the succession of churches over time from ancient times to our own, we see that the former churches were external in nature. Their worship consisted of external actions that symbolized the internal practices taught by the Christian church, whose foundation the Lord laid when he was in the world, and which he is now building for the first time.
Circumcision was the main practice that differentiated the Israelite church from the other churches in the Middle East (and differentiated it later on from the Christian church as well).
Since, as mentioned before [], all the rituals of the Israelite church (which were external in nature) prefigured the practices of the Christian church (which are internal in nature), the primary sign that someone belonged to that church was inwardly similar to the primary sign that someone is Christian. Circumcision represented rejecting the cravings of the flesh, and therefore being purified from evils. Baptism means the same thing.
Clearly then, there are two reasons why baptism was commanded as a replacement for circumcision: (1) to differentiate the Christian church from the Jewish church; and (2) to make it more easily recognizable that the Christian church is internal in nature, which is something the functions of baptism (soon to be covered here [677-687]) make clear.
