Why doesn't the Church have the power to bless homosexual unions?
– Supernatural response of March 15, 2021 from the Congregation for the Doctrine of the Faith on this question argues from the primacy of the person. The Church's teaching offers the truth of human love divinely revealed and accessible to a well-configured reason. According to the plan of the Creator renewed in Christ, marriage is the intimate union of faithful, exclusive, fruitful and educative love, sealed by the commitment between a man and a woman who are free and capable of conjugal covenant.
Sexual difference is inscribed in the spousal language of the body, as a call to conjugal communion, the seed of the family home. The ethical exercise of human sexuality must be lived in a respectful way in the reciprocal gift, and open to the gift of life, within the "we" of spousal love.
Full dignity, wrong choice
While people with homosexual tendencies possess full dignity and always deserve appreciation and help, homosexual acts are a wrong subjective choice. They are completely contrary to anthropological truth. They have absolutely nothing to do with the genuine meaning of human sexuality or the institution of marriage.
The nuptial blessing, which actualizes the divine plan, cannot be imparted to those who have sexual relations that are alien to the reality of the marital consortium, elevated in Christ to the greatness of the sacrament of the new covenant. If one deceitfully or mistakenly seeks to bless same-sex unions, this would cause grave harm to all people, who would receive a false message that immoral, sinful and harmful actions are condoned.
Only true love saves
The Church owes fidelity to God and to man, for she mercifully seeks the good, conversion and holiness of each person and of society as a whole. Only the truth taught by Christ does justice to persons and builds up the human family. Only true love saves.