My postdoctoral research project has as a privileged case of anthropological inquiry the processes of conception, formulation, construction and finishing of the Church of Our Lady of Lourdes - known as the “Indigenous Cathedral” - and carried out by the Salesian Mission in the community of Maturacá (São Gabriel da Cachoeira, Amazonas, Brazil). With the hypothesis that from this temple an “ethnoecological religion” is made, my presentation will seek to elucidate the articulations between ecology and ethnicity that guide the socio-environmental policies carried out by the Catholic Church in the Amazon region. In doing so, my presentation aims to contribute to the elucidation of how the Catholic Church repositions itself in the competition for the Brazilian civic-political space, as an "ecological subject" who starts to defend new socio-environmental policies through a religious repertoire of "social justice" which articulates a certain “ecological imagination” to its consolidated theology of “inculturation”. Therefore, by electing the Indigenous Cathedral as the mediator par excellence of this articulation, it will be through the processes of construction and “public presence” of the new temple that I will demonstrate how Catholic convergences and divergences between notions of ethnicity and ecology materialize religiously on two levels – community and national - in this pluralistic society.