When St. Josemaria received the vocation of 10/2/28, he received a “message” that was not a “general insight into the universal call to holiness…” Rather, he was being shown that “the holiness originating in and founded on baptism to which God is calling Christians is holiness in the midst of the world.” His mission was not in any sense to replace religious orders but "to fan everyone's baptismal grace and channel it toward work and other duties - secular realities which will thereby take their rightful place in people's awareness and daily agenda as the scenario for their 'obedience of faith.' Ordinary life then becomes the setting where one responds to the baptismal call to holiness.” The point is that St. Josemaria did not receive the call to found an institution but to spread the message of the universal call to holiness for everyone, everywhere. But that is the Church herself as institution.
D. Pedro Rodriguez writes that the message "addresses not one particular group, but everyone, with no limitations of gender, race, age, job, social background, civilian status, political views ro secular creed. It seeks only to help to fan everyone's baptismal grace and channel it toward work and other duties - secular realities which will thereby take their rightful place in people's awareness and daily agenda as the scenario for their 'obedience of faith.' Ordinary life then becomes the setting where one responds to the baptismal call to holiness. From the very start this was Josemaria Escriva's apostolic horizon and task; initially, he worked alone at the job God had given him - to do Opus Dei. ... Josemaria Escriva saw with noonday clarity that, in the daily discharge of God's will, spreading the message was inseparably linked to 'convoking' men and women who would make it their raison d’être, committing themselves to carry it to all nations. He saw that the nascent institution was internally dominated by the 'message;' the institution would be the instrument and echo chamber for the God-given message... [So] (t)he message is the first thing God is concerned about; the institution is something he desires insofar as it can spread it. The message, therefore, determines the institution's end, mission and structure; the institution is to be understood in view of the message, which thus becomes the theological criterion to direct and discern the way it develops, institutionally, apostolically or pastorally."
The obvious question: since the Christ has called all without exception (“Be perfect as your heavenly Father is perfect” [Mt . 5, 44], why Opus Dei?
The reason that Rodriguez develops is the same as announced by Escriva somewhere: that the Church always had the doctrine but lost the experience of many people seeking sanctity in the world, and this because of the rise of the religious order after the cessation of the persecutions in the 4th and 5th centuries. The heroism of living the faith began to be lost in the world and the search for heroic love was begun “outside” the world in very narrow circumstances, and particularly not in family life since intrinsic to the emerging canonical religious state was chastity, but understood as celibacy. Absent the experience, absent the consciousness that accrues to it. Sanctity in the world and family life was forgotten as a universal phenomenon.
This brings us to the Synod of 2015 and the formation and search for holiness (self gift: Christian Faith) as integral to its validity as sacrament.