In matters that are so obscure and far beyond our vision, we find in Holy Scripture passages which can be interpreted in very different ways without … - Augustine of Hippo

He who created you without you will not justify you without you.

We may not assent to the teaching even of the Catholic bishops, if at any time they are deceived into opinions contrary to the canonical Scriptures of God; but if they should so fall into error, and yet maintain the bond of unity and charity, let the apostle's saying avail in their case: 'And if in anything ye are otherwise minded, God shall reveal even this unto you.' Now these divine words have so manifest an application to the whole Church, that none but heretics in their stubborn perverseness and blind fury can bark against them. (Cf. Augustine's Reply to Faustus the Manichaean (Contra Faustum), book 11, 5 )

The philosophers who wished us to have the gods for our friends rank the friendship of the holy angels in the fourth circle of society, advancing now from the three circles of society on earth to the universe, and embracing heaven itself. And in this friendship we have indeed no fear that the angels will grieve us by their death or deterioration. But as we cannot mingle with them as familiarly as with men (which itself is one of the grievances of this life), and as Satan, as we read, sometimes transforms himself into an angel of light, to tempt those whom it is necessary to discipline, or just to deceive, there is great need of God’s mercy to preserve us from making friends of demons in disguise, while we fancy we have good angels for our friends; for the astuteness and deceitfulness of these wicked spirits is equalled by their hurtfulness.