I perfectly agree with the two authors above.
But another part of the equation should also not be overlooked, namely the influence the Classical writers had on the holy authors of Christian times. Without any doubt, the early doctors of the Church expected their readers to have at least some knowledge of the literature of their time. How could one, for example, really appreciate St. Augustine without knowing Vergil and Cicero? Every page of his works is riddled with their poetry and prose. Not even mentioning the profound power of Hortensius which played such a big part in the conversion of this great Western Doctor.
Maybe the influence of the Classics is the most profound in earlier times, but it is still very much visible in later ones. It is for example told that St. Gertrude the Great "from being a grammarian became a theologian" - still, her excellent training in the writings of old had a lasting influence. And how could one even understand the meaning of some of her writings without even recognizing all those allegories?
Yes, education was even demanded from the most humble nuns, so much disregarded in these aspects in modern days.
Of course I also have to agree that one has to be carefully prepared for those studies. Without some leadership, that could be quite dangerous. Tertullian speaks of the "catechist of demons", a tutor who knows what to use and what to disregard. And pagan authors should certainly not substitute the Christian ones as done in the Renaissance, as the prothonotary apostolic Jean-Joseph Gaume puts very rightly in his "Le Ver rongeur des sociétés modernes ou le Paganisme dans l'Education" and in his prolonged struggle with the liberal Bishop of Orléans, Mgr. Dupanloup.