The power of God
"And when he had called unto him his twelve disciples, he gave them power against unclean spirits, to cast them out, and to heal all manner of sickness and all manner of disease"
Matthew 10:1 KJV
The Power of God is against demons, sicknesses and diseases and every activity of the devil. So where the power of God is; the works of Satan aren't permitted to continue. Resist demons, sicknesses and diseases and they shall flee from you. It is Written....