Pope Leo XIV appointed Father Giacomo Costa SJ and Sister Elena Massimi FMA last week as undersecretaries of the General Secretariat of the Synod of Bishops, as The Pillar reported. The new appointees step into roles within an office that grew significantly in prominence under Pope Francis and continues to maintain influence under the current pontificate.
Costa and Massimi succeed Archbishop Luis Marín de San Martín OSA and Sister Nathalie Becquart XMCJ. Marín was named papal almoner last year and now serves as a curial prefect, while Becquart’s five-year term expired several months ago without an immediate assignment to a new Vatican post.
While undersecretary positions within the Roman Curia are relatively minor, the General Secretariat of the Synod has drawn heightened attention in recent years. Critics of the synodal process had anticipated that Pope Leo XIV might scale back post-synodal committees or adjust the trajectory established under his predecessor. However, the latest personnel decisions suggest the pontiff is continuing a approach of offering restrained public statements on synodality while assigning positions to figures connected to the established synodal leadership.
Marín’s transition out of the secretariat marked the removal of a moderating presence within the office who is known to be close to the pope. Vatican officials told the outlet that during his tenure, Marín frequently served as a dissenting voice within the office while offering general support for the overarching synodal project.
Costa, his successor, brings extensive experience in previous synodal assemblies and curial events. A Jesuit who joined the order in 1992 and received priestly ordination a decade later following studies in Paris, Costa directed the publication Aggiornamiento Sociali from 2010 until 2021. He subsequently became a consultor to the synod secretariat and played a prominent role in organizing the recent meeting on Amoris laetitia, in addition to serving as a special secretary at the 2018 synod on youth and the 2021–2024 Synod on Synodality.
Publicly, Costa has characterized synodality as secondary to the Church’s evangelical mission, asserting during a 2026 conference that the central focus remains the joy of the Gospel. In 2024, he noted that synods are not parliamentary bodies designed for political bargaining, but rather spaces for discernment. He also supported decisions during the October 2024 synodal session that postponed immediate action on female diaconal ordination.
However, Costa has also authored commentary on sensitive doctrinal and pastoral topics. In a 2016 article following the release of Amoris laetitia, he raised questions regarding the application of natural law norms to pastoral accompaniment. In 2021, he argued that the term intrinsically disordered to describe homosexual relations posed a barrier to communicating Christian teaching to younger generations. Furthermore, after the 2019 Synod on the Amazon, Costa remarked that a distinct Amazonian rite could theoretically allow for married priests, and during a 2022 press conference, he listed Catholics attached to the pre-conciliar Latin Mass alongside gay Catholics as groups feeling exiled from the Church.
Massimi, who fills the vacancy left by Becquart, has built her career primarily in liturgical academia. She made her perpetual profession with the Daughters of Mary Help of Christians in 2009 and earned a doctorate in theology from the Santa Giustina Institute, affiliated with the Pontifical Athenaeum of Saint Anselm.
Currently, Massimi teaches sacramental theology and liturgy at the Pontifical Salesian University, heads the Italian Association of Professors and Scholars of Liturgy, and serves in the music department of the Italian bishops’ conference liturgical office. She also participates in the Synod on Synodality’s study group 11, which examines liturgy through a synodal lens. Her past writings include a 2024 publication endorsing the view that female deacons in the early Church held ordained status, as well as a 2018 book co-authored with liturgist Andrea Grillo addressing ecclesiastical sanctions and institutional perspectives on women in ministry.
