Nobody goes to their doctor and asks for a prescription for evil spirits when they are poorly. Nor do they search for an exorcist as this has satanic implications. Yet all 4 gospel writers believed and wrote about both and as far as I know Jesus never denied this practice or belief when HE healed people. So why do the gospels encourage a practice which is false and if taken literally, dangerous?
I recommend perusing this forum thread from 2016 on exactly that topic:
Wow, I got in big trouble with this one. I believe that Jesus really did heal people suffering from diseases attributed to demons, but the diagnosis was based on an ancient misunderstanding of the diseases. Did people really understand mental illness and epilepsy in those days? Indeed, epilepsy was once called the “sacred disease” because of its association with demon possession I think we should go with modern medicine and prayer.
Some questions: How has belief in demon possession helped to advance medicine? Should the study of demons be added to the medical school curriculum? Might it be that meds for mental illness and epilepsy are actually suppressing demons?
I can only point you to an abstract online, but NT scholar James R. Edwards addressed the question in 'Public Theology’ in Luke-Acts: The Witness of the Gospel to Powers and Authorities. Essentially, Luke is pressing home the idea that Christ is superior to all other so-called “powers” in the world. Some highlights:
Less widely acknowledged is the thoroughgoing attention in Luke-Acts to the powers and
authorities that shaped the world in which Christianity made its debut. The
purpose of the Lukan gospel is thus not only ‘to seek and save the lost’ (Luke
19:10), but at the same time to demonstrate its claim on the authorities respon-
sible for the various orders of life. This latter aspect is the subject of this study.
Luke’s ‘public theology’ is not advanced to denigrate the Third Evangelist’s con-
sideration of the marginal and outcast, but to complement it with an emphasis on
the universal significance of the gospel, which even more than Caesar’s authority
must be taken into ‘all the world’ (2:1).
The ultimate purpose of Luke’s apologetic is not simply to defend the gospel
from false conceptions, however, but to produce a metanarrative that redefines all
powers and authorities in relation to the gospel.
The cosmic significance of Jesus’ Lordship is signalled by Luke’s use of οἰκουμένη, ‘the (inhab-
ited) world’. The gospel destabilises (Acts 17.6;24.5) the counterfeit potentates
and powers to which the world is currently subjected – whether Caesar (Luke
2.1), Satan (Luke 4.5), Artemis (Acts 19.27), famines (Acts 11.28) or eschatological
terrors (Luke 21.26) – in anticipation of the return of Christ to judge the
οἰκουμένη in righteousness (Acts 17.31). In relation to the ministry of Jesus the
authority of the high priests and temple guards and elders is one of ‘darkness’
(Luke 22.52-3), and the ministry of Paul ‘turns the world upside down’ (Acts 17.6).
These various insights and images attest to one overarching conviction: that
the only true power, by which all others – and in all their various forms – must
be made critically accountable, is the name, person and work of Jesus.
First off, I think “demon possession” as a concept has a lot of unbiblical baggage from movies and off-kilter Christian sects, which makes it an unhelpful term in these discussions sometimes.
Secondly, Jesus did not heal people from sickness or spiritual oppression, or feed people, or rescue people from dangerous storms, merely to provide physical comfort. All the miracles were signs meant to establish his authority over everything that incited fear. Jesus had divine power over things humans were powerless to handle; hunger, nature, sickness, all spiritual powers, even death.
I personally believe such signs (including freeing people from the influence of hostile spiritual powers or even raising people from the dead) are still given today in certain parts of the world to advance the gospel. But they aren’t “practices” or “medical treatments” any more than miraculously multiplying bread and fish is a sustainable agriculture technique or singing hymns to cause an earthquake is a viable plan to get out of prison. If you are mentally ill, you should see a medical doctor. But I think it is just as much a false choice to say that all spiritual oppression is really just mental illness with a treatable physical cause as it is to say that all mental illness is really spiritual oppression with no physical cause.