So, they weren't "real" Christians, then?
Nice try, seriously. There is no way to employ the scientific concept of "control" to the subject of whether prayers might be in accordance with the Father's will, (the first Scriptural criteria that I see as being paramount to such a study) or fervent, effectual and done by a righteous person. (3 other criteria clearly given in Scripture)
Now let's consider the design of a research study that
could, at least potentially, yield effective results: (and btw yes I do pick apart many studies, especially in medical related fitness, to expose basic flaws resulting in their conclusions being meaningless)
1) Include only those petitions that are
known to be in accord with the will of the Father, but also have a control group that violates this precept;
2) Create a subset of each category above and the second list of criterion, that the prayer be fervent, "effectual" (a most interesting concept!) and done by righteous people, and also have a control group that violates this.
And what you have is 5,000 + years of Judeo-Christian heritage, doing exactly that.
And greatly to the chagrin of both atheists and religionists who so love to proclaim how divided Christianity is, you see seamless unity in the results of this "research study," and one way of expressing those with the positive results is "the Body of Christ." Which, you'll note, is not exactly something science can study.
(Boy I never thought this thread would go in that direction, thanks for pressing me on this!)