A recent editorial questioned the value of intercessory prayer. In it, a scientific study was conducted which studied two groups of people recovering from cardiac surgery. One group was prayed for and another was not. The results of the scientific study supposedly proved intercessory prayer worthless, and the editorial went on in typical fashion to declare all religion to be worthless and implied God did not exist.
The problem with studies of this sort is that they are based on a false premise from the start, and therefore it is no surprise that they reach ambiguous results. Scientists designing scientific experiments should be more careful, and Christians participating in them should know better. Intercessory prayer is a prayer offered to God on behalf of another person. In this case, it was offered for those who had just had surgery. The important thing to realize is that God has only said He would pay attention to one prayer of someone who has not accepted Jesus Christ as their Savior, and that is a prayer that asks for His forgiveness by the blood of Jesus. That prayer has to come from the person seeking forgiveness. You can't pray someone else into heaven. Therefore, assuming only a small percentage of the recovering patients were Christian, there was no reason to expect God to do anything for the rest. That is not to say that He couldn't have had He wanted to, but He was under no obligation to do so.
The next thing to understand about intercessory prayer is that there are times that God tells people not to pray for someone or some group. For example, in Jeremiah 7, Jeremiah is commanded to not pray for, cry for, or make intercession for the cities of Judah and Jerusalem because God was upset with them and was ready to punish them for their continued worship of other gods. In cases like these, you can't expect God to answer your prayer because He is angry with a particular group and if you do pray when He tells you not to, you could also be in trouble. This isn't a judgment on the group that was prayed for in the study - just an observation that God is sovereign and has His own will that you won't bend. Even Abram pleading for Sodom to be spared if a certain diminishing number of people were found who were righteous realized there was a limit and didn't push beyond that limit when he knew that God was angry. Even though he interceded on the behalf of the cities, there weren't enough righteous people found and they were destroyed (Genesis 18).
So the results were completely unsurprising for this "scientific" study, based on invalid suppositions.
When is intercessory prayer ok then? Well, we are told often to pray for each other. We are told that the Spirit of God and Jesus Christ himself make intercession for us (Rom 8:27,34). This intercession is always in the will of God so is always appropriate. Those who are Spirit filled are told to pray in the Spirit, because when praying in the Spirit, we know that we are in tune with the Father's will (Rom 8:26). Finally there are many general commands to pray for our fellow brothers and sisters in Christ, again being sure that we are praying in the will of the Father. God has provided many promises for us to live by. We can count on His promises. But we must also remember always the warnings in James and other places that we pray for things that are actually in His will and not for things that are wants that we have to lavish on our own fleshly desire (Jas. 4). Many times what we pray for falls in that category.
When it comes to healing, should we pray for people to recover after surgery? I don't think it necessarily hurts if something new is going wrong. But keep in mind that the glory for God is to heal someone's condition before doctors get involved.
In our Sunday School class we prayed for a lady's husband who was due to undergo surgery the next day. Others in their family and the church prayed for him. In our class, we prayed that God would heal him so He didn't have to undergo surgery at all and when he got to the hospital the next day he was feeling better. They did tests and decided he was fine and didn't need surgery at all. I can't answer why everyone isn't healed. I've had to have surgery myself and would have liked to be healed, but I'm not the greatest Christian at times so I wasn't upset with God at all that He didn't. But we have a result in the last couple of months when intercessory prayer worked and God got all the glory. God didn't have to share it with doctors.
Another lady in the class reported she was having heart pains late one night and knew that she should go to the hospital since she already had had a stent put in one of her vessels. But she decided she would leave it in God's hands. She made it through the night with a peace from God, and the next morning her daily Bible reading from Psalms talked of God strengthening the heart. She hasn't had any pains since.
In our own family, we have had one person healed of something the doctors had no cure for by going to the front of the church and being prayed for by a Spirit filled lady. The immediate physical change in her body was like night and day. God is good. The lady praying for her said she might need prayer for the condition again, but it has now been several years and the condition has not returned. Praise God for His love for us!
God still works miracles and heals His people. Everyone isn't healed now, any more than everyone was healed in Israel when Jesus walked among them. But many were then and many are now. If you need a touch from God ask for an increase of faith. Ask for His promises to be kept in your life. Make sure you are where you need to be with Him. Make sure what you are asking for is in His will. Leave it in His hands. If He doesn't answer your prayer - go to the hospital or a doctor. Maybe He wants you to witness to someone there and the only chance they will ever have to know God is if you get sick. Perhaps your getting sick now - even if it is to death - will prevent you from falling away from God later and ending up in hell! Never doubt God's wisdom or knowledge about you and what you need. If He does choose to heal, tell the world! If you have medical proof of a before and after nature all the better!
Remember God is on His throne. He's the boss and He knows best. Trust in Him. If God is calling you to pray for someone, pray. Intercessory prayer works. If He's telling you not to pray for someone, then don't and see if there is something else He wants you to do. But never doubt that God is and His promises are always carried out if we ask according to His will for us or for someone else.