The Church does not have the power to bless same-sex unions. It is thus not licit for priests to attempt such blessings, and they cannot “be considered licit,” according to the Congregation for the Doctrine of the Faith (CDF), which issued March 15 a Response to a dubium (a question) that had been presented on this issue.
You can find the full text of the Response and explanation, here.
Also, you can read the commentary on the Response, provided by the Vatican press office, here.
Pope Francis gave his assent to the publication of the Response and an accompanying Explanatory Note signed by the Prefect, Cardinal Luis Ladaria, and the Secretary, Archbishop Giacomo Morandi.
Vatican Media noted:
The statement is based on specific assertions and some actual practices. The document situates its Response into the context of the “sincere desire to welcome and accompany homosexual persons, to whom are proposed paths of growth in faith,” as expressed also in the Apostolic Exhortation Amoris laetitia, which speaks of “the assistance they [those who manifest a homosexual orientation] need to understand and fully carry out God’s will in their lives.”
Therefore, pastoral plans and proposals in this regard are to be evaluated, including those concerning the blessings of such unions.
Fundamental to the CDF’s Response is the distinction that must be made between ‘persons’ and ‘union.’ The negative response given to the blessing of a union does not, in fact, imply a judgement regarding the individuals involved, who must be welcomed “with respect, compassion, and sensitivity” avoiding “every sign of unjust discrimination” as already written in Magisterial documents.
These are the motivations at the basis of the negative response. The first regards the truth and value of blessings, which are ‘sacramentals,’ liturgical actions of the Church which require that what is being blessed be “objectively and positively ordered to receive and express grace, according to the designs of God inscribed in creation.”
Relationships, even if stable, “that involve sexual activity outside of marriage” – meaning, outside “the indissoluble union of a man and a woman,” open to the transmission of life – do not respond to the “designs of God,” even if “positive elements” are present in those relationships.
This consideration not only concerns same-sex couples, but also unions that involve sexual activity outside of matrimony. Another reason for the negative response is the risk that the blessing of same-sex unions may be mistakenly associated with that of the Sacrament of Matrimony.
The CDF concludes by noting that the Response to the dubium does not preclude “the blessings given to individual persons with homosexual inclinations, who manifest the will to live in fidelity to the revealed plans of God,” while it declares impermissible “any form of blessing that tends to acknowledge their unions as such.”
Can a homosexual person become a saint? The answer is ‘yes.’