Churches who strongly believe in healing will tend to look at the 4 gospels and early Acts. It is understandable since so many healings took place then.
But they forgot that Jesus and the 12 were given signs to testify to Israel that the Messiah had arrived. Those healings were not random acts of kindness but for a specific purpose.
Its very hard to have a strong case for healing based only on Paul's instructions to the Body of Christ, which is Romans to Philemon. You will encounter difficult issues like "Why did Paul advise Timothy to drink wine because of his illness, when Paul's hankerchiefs could heal anyone during Acts?