@Thomas, you would know as well or better than anybody here:: Was there ever a time over the years where studying or honoring the classics was considered a threat to Christian theology or belief? What about the concepts of "muscular Christianity" or "civil religion" - to your knowledge, have those been considered threats to Christian belief?
Ooh, there's a big question!
I'd start with St Paul – in Acts 17 he quotes two Greek poets in quick succession, both poems addressed by their writers to the god Zeus. St Paul situates them in a Christian context. From the Fathers on, it was accepted that Christian revelation contextualised pagan practice. So the classics were studied, and to some degree venerated, but not blamed or condemned for being unaware of the Truth as proclaimed by Jesus.
St Thomas Aquinas, for example, referred to Aristotle as 'The Philosopher' in his
Summa Theologiae, and married the 'Aristotelian method' (the foundation of good scholarly practice) to his theological practice. The Church founded universities and the classics were taught there. (Aquinas quoted Aristotle extensively, as he did Augustine and Dionysius the pseudoAreopagite, those two being Platonists.)
The clerical garb of today – black attire – was copied from the Greek philosophers.
Conversely, there is an ever-present 'pastoral concern' to protect the laity from 'deleterious paganism' which all too often and too easily devolved into a 'ban' on anything regarded as 'dangerous' – and so there was always the issue of Christian scholars being accused of heresy – Valentinus, for example, or the scandalous condemnation of the likes of Origen and Meister Eckhart.
This unfortunate practice is even more overt in conservative Christian circles today, with the banning of books and certain teachings, etc.