I'm not even sure it's proper to oppose πίστις to "reason". If you understand the word in a sense closer to "trust" then the opposition doesn't even seem coherent. I do not have, in a sense opposed to reason, "faith" that my father loves me, but I do have πίστις. Or, for a negative example, Othello has not lost "faith", in a sense opposed to reason, in Desdemona, but he has lost πίστις for her, and in that case reason become destructive of the marriage and the tool of Iago.

Alexander wrote:

As for an "obligation to believe", I think that might be too strong a way of putting it. We have reasons to believe what is revealed; given these beliefs, we have obligations to act in certain ways. I'm not sure we have an "obligation to believe" anything.

Is it possible to achieve salvation without belief in the doctrine of the trinity?

In any case, I'm not sure what your argument is against my two points.
(a) Faith does not follow necessarily from rational arguments. This is surely uncontroversial. Even if faith is reducible to "conviction in one's beliefs", such conviction does not always arise from even the best philosophical and scientific arguments. There is always a degree of subjective "assent" to an argument's conclusion. And if faith is not so reducible - perhaps including ideas like "trust in the authority of another" or "willingness to follow the commands of another" - it's even more obviously not going to follow from most forms of argument.

And I would assert that faith is only mandated insofar as the idea is rational, as opposed to arbitrary.

(b) Faith does not have to be born of reason. This seems again uncontroversial. Most people who have faith have not studied the philosophical arguments surrounding their beliefs, and it seems unusual to condemn them for this, especially if they are not capable of doing so.
 

While undeniably helpful, such uninformed faith is not that which is demanded of man. I simply don't see the difference between this and the Hindu who has faith because he trusts the Maharaja.

If your question was specifically "why should we believe Trinitarian doctrine?", the obvious (though unhelpful) answer is "because we take it to be revealed by God". If your question is more generally "how do we know that something is revealed by God?", this is certainly harder to answer, but it is faced by all putative revelations, not just Christianity.

It was the latter. And I recognise the problems that poses for all revelations, and as such I tend towards the (somewhat heretical) position that if a man does all he can to understand and yet still doesn't find the Mosaic revelation convincing he is not guilty in the eyes of God.
 

DanielCC wrote:

Etzelnik wrote:

It was the latter. And I recognise the problems that poses for all revelations, and as such I tend towards the (somewhat heretical) position that if a man does all he can to understand and yet still doesn't find the Mosaic revelation convincing he is not guilty in the eyes of God.
 

Out of interest what is Orthodox Judaism's position on the Noahide Laws? Can they be known via reason alone?

 
Obviously, there is a range of opinions, but it's fairly mainstream to maintain that the Noahide laws are such precisely because they are quite self-evident by reason.