But we have seen that Paul was abandoned. Consequently, during the first centuries, the great majority of Christians thought they had to form a visible organization, a church which would replace the people of Israel or absorb them. They then attempted to adapt to this church the ancient prophecies, the covenants, the ceremonies, feasts, gifts, in short all that belonged to Israel or related to the time when that people were still the elected people. Aided by political circumstances in the later Roman Empire, a kind of unity was achieved. It was, however, rather precarious, for the history of Christendom is replete with quarrels, fights, and divisions. Later on, attempts were made from time to time to better understand Paul, but the power of human tradition is such that theologians have never been able to free themselves from it. They have continued to base their studies upon the a priori that a "true Israel" (i.e. "the church") has replaced the "symbolic" Israel (i.e. the religious and political Israel of the OT).
Nevertheless, just as Israel's disobedience to the divine Word did not prevent individuals from partaking of the blessings, similarly the failures of the mass of Christians during our present period do not present an obstacle to the Christian thirsting for the Truth. No obstacle exists which would prevent him from studying the inspired Word, from being enlightened by the Holy Spirit in order to understand Paul and follow him in his solitary course. As in the case of the apostle, he risks being abandoned "by all." However, a faithful believer will be able to go on from glory to glory, in ever increasing intimate communion with the Lord, always able to better bless Him for His overabundant grace.
from pages 162- 163, The Teaching of the Apostle Paul