To postulate means to ask, to ask, to request … In the language of canon law, it is the request to promote a cause for beatification or canonization in the competent ecclesiastical tribunal.
Who can ask for the opening of a cause for beatification? The promoting group (ActorCausae) can be a diocese, a parish, a religious congregation, an association that through the postulator asks the bishop to open the investigation.
A physical person can also be an actor in the cause, that is, anyone who is part of the People of God, provided he is able to guarantee the promotion of the cause in its diocesan or eparchial phase and in the Roman one.
3. The bishop of the diocese in which the person whose beatification is requested died is competent to begin the investigation. The promoting group (ActorCausae): diocese, parish, religious congregation, association, through the postulator asks the bishop to open the investigation.
The bishop, having obtained the authorization from the Holy See, establishes a special diocesan court. Before the Court, witnesses are called upon to report concrete facts.
v.tr. [from Lat. postulate “ask”] (I postulate, etc.). – 1. (lit.) [addressing someone to obtain a favor, a benefit and the like: postulate a recommendation] ≈ ask, ask, request. ↑ demand, complain. ‖ Begging, …
Why For the Catholic Church, holiness is the goal to be achieved for the faithful.