The power of intercession can be scientifically, scripturally and specifically attested. There is more scientific evidence for answered prayer, than any scientific statement that is capable of proof.
History abounds with such proof.
A diary faithfully kept over only a few months will show many thrilling, and positive God-given answers to specific petitions. There is also the evidence of remarkable changes in both the intercessor and the ones interceded for. No-one can spend regular and prolonged times in intimacy with God and remain unchanged. He is a rewarder of them that diligently seek Him. Let everyone who regularly intercedes for others and their needs, keep systematic records, and from time to time have a special thanksgiving meeting with God for all the factual things received.