(note that this post is a new thread branching from this comment; on this blog)
You asked on what do we base our claims (or at least the particular claims in question here). This is another topic that I wanted to press/explore with you, because it seems that we differ on what gives validity and weight to the things on which we base some of our claims.
To begin, is there “a basis” for a claim that is as nuanced and multitentacled as the good life? To name a paltry handful of things that I consider are a part of “life to its fullest”: my relationships, my health, and my leisure. Life to its fullest is comprised of many different things, and the validity of each of those things is not necessarily based on the same thing. We base good health care on something different than what we base good relationships. Both are valid, but based on different criteria (this way of thinking about what gives things meaning is based on Ludwig Wittgenstein’s work, particularly with regards to his work in the Philosophical Investigations).
Rational proof (scientifically speaking) is the basis for some of the things that make our up notions of the good life, but there are numerous other things that make up the good life that are based on things that are not validated by the scientific method. You could use the language of scientific evidence to base your claims on what makes a marriage “good.” But on what would you base the claim that these aspects of life need to be based on the same claims as science? (I know that was convoluted)
So the short answer is that your question cannot be answered in generalities. To be fair, I’ll try to express what I think makes a relationship good and how my belief in Christ plays into that. I anticipate the response to whatever rationale I give to be, “why do you need a belief in Christ to believe that?” This is a fair question. But why do we need Darwin in order to affirm certain theories of revolution; why do we need Einstein to believe the theory of relativity. We could argue that these things could have been discovered without these men, but why would we want to distance the people from their discoveries? More to my point, if I felt that someone had given me a great gift, what good reason would I have to drive a sharp distinction between the gift and the person that gave me that gift, when in fact they are intimately connected. Similarly (and this only plays a minor part in my rationale), to ask why I would need Christ in order to affirm the all of good things in my life that exist because of him seems to be dishonest.
Christians can say that it is because of Christ that we have friends who are men and who are women; black and who are white; who are heterosexual and who are homosexual. It is because of Christ that we can see the power in loving our enemy, and even accepting death at their hands rather than inflicting it ourselves. It is not only because of Christ that I we empathies with those suffering injustices, but also because of Christ that we see some things as unjust while others may not, like abortion. I could go on to tell of all of the ways in which I have trusted in my faith and that it has only led an abundant life (of course the word “abundant” has a very particular definition within my faith, and it does not refer to monetary things).
I understand that this doesn’t constitute proof. Nor does it prove any other religion as “wrong.” But you asked on what I base my claim, and it is the fact that I have lived out the aforementioned (which is only a small list), and have seen it as “good” not merely for me, but “good” for an entire community.
I feel bad for the long post (that could have been much longer), but I am particularly interested in the conversation of what constitutes a valid basis. As you can probably guess, I’m assuming that we differ on this topic. At any rate, thanks for the conversation thus far.