what does this mean

Like, yes, a lot of Catholic clergy during the Middle Ages did practice magic in secret, but they weren't keeping it secret as some sort of sinister top-down conspiracy to deny magic to the Common People: they were mostly keeping it secret from their own superiors. It wasn't one of those "well, it's okay when we do it" deals: the Church very much did not want its local priests doing wizard shit. We have official records of local priests being disciplined for getting caught doing wizard shit. And the preponderance of evidence is that most of them would take their lumps, promise to stop doing wizard shit, then go right back to doing wizard shit.

In brief, the idea that magic is a. real and b. Satanic was not the party line for the greater part of the Middle Ages. Obviously the particulars varied both regionally and over time, but for the most part, the official position of the Church was that there is no power but God's and magic is fake. The Church's principal objection to the practices of divination, spirit-binding, etc. was that they were fraudulent, not that they imperilled one's soul. Sometimes this was even carried to the point that accusations of witchcraft would result in the accuser getting in trouble rather than the accused; after all, if your neighbour is pretending to do wizard shit, that's fraud, but if you actually believe your neighbour is capable of wizard shit, that's heresy!

The boring stereotypical Bad Middle Ages take is that medieval people were all howling misogynists and thus were burning Female Witches (and also midwives, out of an idea that medieval people saw all female-led intellectual practice as inherently bad, which is also uh, questionable) at the stake left and right. As I have carped about many times, Witch Trials (TM) as most people think of them were decidedly an early modern invention. The idea of witchcraft as both a) real and b) specifically and evilly female was also in fact a very late medieval invention; it was most explicitly codified in the infamous Malleus maleficarum of 1485. However its author, Heinrich Kramer, was already a raging misogynist and had been chased out of his parish the year before when for some reason, people got tired of him randomly accusing their wives and daughters of witchcraft. The Malleus is well known as a "witch hunting handbook," but people then tend to generalize its late 15th-century conclusions, written by one tiresome misogynist, as completely representative of The Middle Ages Everywhere. The Malleus also contains some anti-sodomitic polemicals, so there are just a whole stew of gender, queer, and other anxieties being represented here in a late medieval context. See i.e.:

Bailey, M. D., ‘From Sorcery to Witchcraft: Clerical Conceptions of Magic in the Middle Ages’, Speculum, 76 (2001), 960-90.

Bailey, M.D., ‘The feminization of magic and the emerging idea of the female witch in the late Middle Ages’, Essays in Medieval Studies 19 (2002), 120-134

Broedel, H.P., 'To preserve the manly form from so vile a crime: ecclesiastical anti-sodomitic rhetoric and the gendering of witchcraft in the Malleus Maleficarum', Essays in Medieval Studies 19 (2002), 136-148

Broedel, H.P., The Malleus Maleficarum and the Construction of Witchcraft: Theology and Popular Belief (Manchester: Manchester University Press, 2003)

Harley, D. ‘Historians as Demonologists: The Myth of the Midwife-Witch’, Social History of Medicine, 3 (1990), 1-26

Katajala-Peltomaa, S. ‘A good wife? Demonic Possession and Discourses of Gender in Late Medieval Culture’, in Gender in Late Medieval and Early Modern Europe, ed. by M.G. Muravyeva and R.M. Tovio (New York, NY: Routledge, 2013), pp. 73-88

Stephens, W., ‘Witches who steal penises: impotence and illusion in the Malleus Maleficarum’, Journal of Medieval and Early Modern Studies 28 (1998), 495-529

It's true that some of the most dedicated practitioners of ritual magic, and scholars and conservationists of magical texts, were monks, churchmen, and other religious figures. Some of them started from the position that God possessed the only supernatural power and any claim of other magic was wrong, but many others did believe that magical power was accessible from a variety of sources, even as this interacted uneasily with related notions of heresy, religion, blasphemy, and (demonic) sin. This represented the complex and shifting interaction between institutional Catholic and traditional/folk magic beliefs, which were never fully assimilated or "erased." It was in fact also popular among laypeople, as magical amulets or charms were highly valued for their supposedly protective capacities. Magic and ritual magic was also widely used in medicine and yes, for sex (people have always been people etc. etc.). See i.e.:

Bailey, M. D., Battling Demons: Witchcraft, Heresy and Reform in the Later Middle Ages (University Park, PA: Pennsylvania State University, 2003)

Boureau, A., Satan the Heretic: The Birth of Demonology in the Medieval West, trans. by Teresa Lavender Fagan (Chicago, IL: University of Chicago, 2006)

Collins, D., ed., Cambridge History of Magic and Witchcraft in the West (New York, NY and Cambridge: Cambridge University Press, 2015)

Fanger, C., ed. Conjuring Spirits: Texts and Traditions of Medieval Ritual Magic (Stroud: Sutton, 1998)

Flint, V. I. J., The Rise of Magic in Early Medieval Europe (Oxford: Oxford University Press, 1991)

Kieckhefer, R., Magic in the Middle Ages (Cambridge: Cambridge University Press, 2000)

Kieckhefer, R. ‘Erotic Magic in Medieval Europe’, in Sex in the Middle Ages, ed. by J. Salisbury (London and New York, NY: Garland, 1991), 30-55

Olsan, L.T., ‘Charms and Prayers in Medieval Medical Theory and Practice’, Social History of Medicine, 16 (2003), 343-66

Page, S. Magic in the Cloister: Pious Motives, Illicit Interests and Occult Approaches to the Medieval Universe (University Park, PA: Pennsylvania State University, 2013)

Rider, C. ‘Danger, stupidity and infidelity: magic and discipline in John Bromyard’s Summa for Preachers’, Studies in Church History, 43 (2007), 191-20

Meanwhile, back in the village, the priest did the mediaeval equivalent of leaving that nonsense on Read, and at planting time of course made sure to help the village people bless their fields, because look planting time is important.

In some cases he also willingly shared a bit of the communion wine to the local cunning woman (who was also probably the midwife), since that was the best thing to mix into ointments and potions for everyday ailments. But only a little, of course, as it was precious stuff.