Joining the Order means taking on a commitment for life. The commitment is to be a Witness to the Faith, to lead an exemplary Christian life of continuing charity in support of the Christian communities in the Holy Land, and to maintain the true charitable commitment of a Christian. The purpose of an individual in joining the Order should be to serve the Catholic Church and to support the efforts of the Church and the Latin Patriarchate of Jerusalem to maintain the Christian presence in the Holy Land.

Usually, though not invariably, a candidate is introduced by an existing Member of the Order. Suitable candidates are usually identified on the basis of their contributions (in all senses) to their parishes and to the wider Catholic Church, and of their interest in the specific aims of the Order. The candidate must be a baptized Catholic, in good standing with the Church. The Delegate and/or Section Head with jurisdiction over the area in question will assess the candidate at an initial interview. If, after this interview, both sides feel that it is appropriate to move forward, the candidate will begin a period of formation, lasting approximately a year, in which he/she will attend a number of instructional and devotional sessions. If the candidate duly completes this formation period, he/she may apply for admission to the Order through the local Lieutenancy, which will review the application and then pass it on to the Grand Magisterium, in Rome, for final approval.

New Members are admitted to the Order, and existing Members may be promoted, at formal Investitures, usually held at a cathedral or major church within the Lieutenancy. Lieutenancies generally hold their Investitures, which all Members are expected to attend regularly, once or twice a year. Where individual Lieutenancies cover large geographical areas, as in North America, there is usually only a single annual Investiture. Sections and Delegations also host local Masses and other meetings, at varying intervals.