What about non-Christian religious practices, though morally and spiritually valuable? There is a notion that one religion is pretty much the same as another, but the Church wants to ensure that message is not what is communicated through the rites.
47. The liturgy is the expression of faith and Christian life, and so it is necessary to ensure that liturgical inculturation is not marked, even in appearance, by religious syncretism. This would be the case if the places of worship, the liturgical objects and vestments, gestures and postures let it appear as if rites had the same significance in Christian celebrations as they did before evangelization. The syncretism will be still worse if biblical readings and chants (cf. above No. 26) or the prayers were replaced by texts from other religions, even if these contain an undeniable religious and moral value.*
* These texts can be used profitably in the homily because it is one of the tasks of the homily “to show the points of convergence between revealed divine wisdom and noble human thought, seeking the truth by various paths” John Paul II, apostolic letter Dominicae Cenae, no. 10.