Christians disagree much on the application of the passage in James. Some reject it as a practice for today. Some try to obey it exactly as detailed in James and do it only when someone specifically calls for the elders of the church. Others go much further than James and make it a regular part of some sort of healing service. I can only give you the conclusions I reached a few years ago after studying the issue. Here is the passage in question:
James 5:14-15 Is any sick among you? let him call for the elders of the church; and let them pray over him, anointing him with oil in the name of the Lord: And the prayer of faith shall save the sick, and the Lord shall raise him up; and if he have committed sins, they shall be forgiven him.
I greatly oppose those who make a mockery of this passage by setting up healing lines at healing services and use this passage to support their actions. As we shall see, this passage does not support the practices of healing services. The New Testament church was never commanded to have such services. However, I have no serious opposition to those who practice anointing of the sick when they call for the elders of the church according to the instructions in James. I know that they are just trying to obey the scriptures. But I personally do not anoint the sick as a practice. I believe it was a part of the age of the apostles and connected with other gifts such as speaking in tongues. The book of James was written early--during the time of the book of Acts. The changes that would take place with the completion of the New Testament had not yet taken place. Let me give you seven reasons I do not anoint with oil.