Not all the sick brought to Jesus were oppressed by demons. Matthew 8:16 puts the demon-oppressed and the sick in separate categories. People brought so many to Jesus who were oppressed by demons because they knew of his earlier liberation of a demon-oppressed man in the synagogue of Capernaum (Mark 1:23–27). Others were sick simply because of the general brokenness of our world under the curse of sin. Jesus’ power is fully capable of ending both types of suffering.
No, Matthew 8:16 specifically distinguishes between those who were oppressed by demons and of which demons had to be cast out, and those who were healed from other types of illnesses. The fact that they brought so many who were oppressed by demons to Jesus that evening must be understood in light of the fact that earlier that same day Jesus liberated a demon-oppressed man in the synagogue of Capernaum (Mark 1:23–27). According to modern science such miracles are not only uncommon or unnatural but even impossible, but for Jesus these miracles indeed came quite naturally. As such it is also here emphasized that Jesus healed everyone who was brought to him, regardless of what illness they suffered from.1
The distinction between demon oppression and other illnesses needs to be understood in light of the nature of the illnesses themselves. The former refers to the direct inworking of demons, while with the other illnesses it is the natural consequences of the outworking of sin in the world. As such Matthew 8:16 provides an overview of the people brought to him which simply serves to highlight the fact that Jesus healed everyone.2
16 Le soir, on amena auprès de Jésus plusieurs démoniaques. Il chassa les esprits par sa parole, et il guérit tous les malades,