I don't believe I've made any argument about prayer..
I apologize for misreading. If I recall correctly, your claim was the following. Because my religious views exert a measurable impact with respect to my life, I know that my religious views are true. Your wording was different, you stated you know that they are based on true principles. I think in this case the word principle was used out of place and the substitution of principle for 'my beliefs' is legitimate. A principle is merely a theoretical model that describes how things work.
Another way to frame your claim is as follows: if I have a belief regarding how the world works, one way for me to see whether or not it is true is to apply it to the world, if it works the way I thought it would, then its true. For example, if I am a Nazi who wants to shoot a jew and I have a belief that I can accomplish this goal by operating a gun in a certain way; I can discover if my belief regarding the use of guns is true by attempting to shoot a jew. If I do shoot him then I can conclude that my belief regarding the gun use is true.
My objection was that one successful shooting act is not conclusive evidence for my gun operating competence as for all I know it could have been the case that I fired the gun accidentally; or the action I performed will not always cause the gun to fire. We would need many more of such incidents to procure evidence for my competence using a gun.
Your main argument with respect to religion is as follows, at least as I understand it. A very small portion of Christians sincerely and fundamentally accept the authority of the Bible, most do not. However, out of this small group, an overwhelming majority show a marked ethical improvement in their lives?
Is this so? Can you cite any empirical studies on this topic? It certainly seems unpersuasive. History is full of examples of men of the highest piety possible behaving in a morally disreputable manner. Priests; for example have been accused of pederasty. One may say that the priests were simply problematic people and religion did not at all contribute to their decadence, it actually helped them; they would have been far worse off if they did not endorse any religious views. This seems unpersuasive as many of them showed no sign of licentiousness until later on in their career. They must have appeared quite pious to many astute judges of character in order to have become priests. The argument that they always were salacious is unpersuasive because if they truly were, it is difficult to believe that they could have duped every relevant astute critic to believe that they are morally irreproachable. You may say they are a minority of true Christians who do not show a marked improvement. Very well, but what about the common-place preacher? Religious moralists are widely accused of hypocrisy and for justifiable reasons. A significant portion of preachers indeed do not practice what they preach. But then again, you could respond that there are other, extra-religious factors in the situation that make them behave immorally; for example, the heavy political circumstances of their lives often seduce them into illicit behavior. If men of such ardent faith weren't forced to function as politicians, their lives would have shown an ethical improvement. In short, in this case Christianity did improve their lives, but this was overshadowed by other circumstances that pulled them towards wickedness.
Very well, if those examples of mine aren't acceptable; what about the thousands of religious fanatics who kill people in the name of Christianity? They believe that they accept the authority of the Bible, yet nonetheless they engage in savage-like behavior. (For example, mothers who drown their babies in the name of God or Christians who bombed abortion clinics)
You may say that they are simply misreading the Bible and are not truly accepting its authority. Yet in that case, how do you know what interpretation of the Bible is a true depiction of its authoritative voice? It is a book that has been written in a culture dating thousands of years back: many of its expressions depend heavily on culture specific factors such as the customs that were endorsed at the time and figurative expressions such as allegories and idioms that are not easily understood by members of a different culture. Indeed, the proper interpretation of many passages of the Bible has been the subject of controversial debate for scholars of biography, literature and history. No clear-cut consensus has been established with regard to the nature of the thorough and an educative message of the Bible. The message extracted by these scholars certainly is not thorough and educative enough for a person to base his worldview on. At this point we simply do not have a clear enough of an understanding regarding the proper interpretation of Biblical passages as well as the context that they are environed in.
In summary, I have cited various problems regarding the suggestion that people who truly accept the authority of the Bible show a marked ethical improvement in their lives. First of all, not all of them who claim to have truly accepted the authority of the Bible do. Its not at all obvious that the people who do improve are the majority. You can't just bracket those who don't show the improvement under the justification that those people did not truly accept the authority of the Bible because the correct interpretation of the Bible is not at all obvious.
On the other hand Christians which said they believed in the authority of the Bible and engaged in "costly" behavior did have a statistical improvement in behaviorTheir type of religion is actually potent, because it is more effective than the default level of Christianity. ..
I have expressed my objections regarding this claim above.
This is the type of "experiment" that can't be repeated in practical terms. It's a one shot deal. Let's connect the scenario more with real events. If Alexander the Great claimed he was destined to be a great conquerer then he'd be correct. If Saddam Hussein claimed that he was destined to be a great conquerer then he'd be incorrect. In either case we have to make a decision based on the information we have. ..
We don't have to make a decision based on the information above, we can postpone the decision until the mroe suitable information arrives. Only by doing so will we be able to avoid making an inductively weak argument.