James 5 - praying for the sick

One of the most difficult passages in the New Testament in some ways is in James 5. Here's the NIV...

Is any one of you sick? He should call the elders of the church to pray over him and anoint him with oil in the name of the Lord. And the prayer offered in faith will make the sick person well; the Lord will raise him up. If he has sinned, he will be forgiven. Therefore confess your sins to each other and pray for each other so that you may be healed. The prayer of a righteous man is powerful and effective.
James 5:14-16, NIV

Any attempt to argue that this passage doesn't say that anyone who is sick will be healed sounds either like special pleading or like finding contradictions in the Bible. Of course, part of the problem is the translation, and pretty much no English translations manage the same nuances as the Greek...

Is anyone in you weak/sick (the Greek can mean either)? Let him call the elders of the church and let them pray on him, anointing with oil in the name of the Lord. And the prayer of faith will save the wearied / ill person (the Greek can mean either); and the Lord will raise him...

It looks to me as if the first bit is a general statement which is deliberately ambiguous. It might be talking about physical sickness; it might be talking about physical or moral weakness or weariness. And the promised help is salvation / raising, which might be talking about physical healing, or it might be talking about final salvation.

There is then a clear application to the case of people who are ill because of sin (for example because they rightly feel guilty, and the guilt has led to all kinds of stress-related problems), and they will be healed. By verses 19-20, the passage is all about bringing people who have sinned back.

My conclusion from this passage is that the passage itself does not promise immediate physical / medical healing for everyone who gets the elders to anoint and pray, except in the case of sickness that is directly due to sin. Of course, God still does sometimes heal physically and medically in other cases, but he doesn't promise here that he will do so. What is promised is something far better. What this passage promises is that God will sustain and keep his people going when they are weak and get the elders to pray for them, and that they will finally be saved and raised from the dead; if they ask the elders to pray for them then like this then no sickness or weariness or sin committed in the past can stop them from being saved.