Sigurd Grindheim, «What the OT Prophets Did Not Know: The Mystery of the Church in Eph 3,2-13», Vol. 84 (2003) 531-553
The purpose of this essay is two-fold. First, it argues that the inclusion of the Gentiles is referred to as a previously unrevealed mystery because it is based upon the abrogation of the Mosaic law and entails a degree of nearness to the Lord that exceeds the expectations of the old covenant. Second, it addresses the question of authorship. Assuming Pauline authorship as a working hypothesis, it shows that the use of the concept of mystery in Eph 3 is intimately linked with Paul’s terminology and thought world attested in the undisputed letters. It is unwarranted, therefore, to find proof of a post-Pauline development in the use of the term "mystery" in Ephesians.
terminology and thought world. Rather than seeing here the work of an ingenious imitator, therefore, it is better to explain the letter to the Ephesians as the apostle’s re-formulation of his ideas in a new situation75.