The rite of circumcision was by no means peculiar to the Jewish religion (Jer. ix. 25, 26), except perhaps in so far as it was performed in infancy: its origin and growth are very obscure. Its original significance was early lost and its interpretation was probably due to the Prophets themselves, who often referred to a spiritual circumcision, and thus made possible the full ceremonial interpretation which became so important a feature in later Judaism.
We have seen that there is evidence to prove that the religion of Israel had not always been averse to the use of idols as part of the legitimate worship of Jehovah. The Prophets began the protest against this, not so much because of its principles, but because of the immoral practices with which idol worship was connected. But after the Exile, idolatry was for ever separated from the worship of Jehovah, and in the later Prophets idolatry becomes the target for their most scornful invective. It has been suggested that this new abhorrence accounts for the non-return of the Ark, which in this period disappears from history.
Among the most important of the new institutions that can be traced back to the period of the Exile is the founding of the Synagogue. In the land of Exile, away from the one spot where sacrifice was permitted, worship had to be carried on without the aid of sacrificial or ceremonial rites, but there was nothing to prevent the people from gathering together for prayer or to hear read their newly reverenced prophetic books. It is quite possible that this led to a collection of the Prophets' writings being made, and perhaps to some editing to meet their present needs. This movement was of profound importance for the future development of religion, for it was in the Synagogue rather than in the Temple that Christianity was to find the readiest medium for its dissemination and the earliest model for its worship. The Synagogue itself prepared the way for the more spiritual developments within Judaism, for away from the Temple sacrifices and their always dangerous suggestions men learned that the sacrifice of the broken heart was more acceptable to Jehovah; and so the way was prepared for that magnificent collection of prayers and songs which we call the Psalms, which were afterwards to be used as an accompaniment to a form of worship that they frequently condemn. The external and legal conceptions were, however, to be the most visible results gained from the Exile, and they were to mould religion for many a year.