There is no reason why the God discovered by philosophers should not be identified with the divinity of a given religion, if philosophers do find a way to affirm a God (as many have claimed to do).
This is something often forgotten from both sides. To the religious person, a philosophical account of God may seem like hubristic idolatry, and to the person who accepts such an account, any religion may seem like nothing more than rank superstition.
In premodern times, though, there was a sort of middle way that held considerable influence, which is likely not even to occur to many people today as a possibility worth considering. It was neither rational to the exclusion of faith, nor fideistic to the exclusion of reason. That’s not to say that in antiquity and the Middle Ages no one ever fell into the one extreme or other, only that the third option, the possibility of a synthesis, was a much more dominant intellectual possibility, eventually really winning the day.
Now, someone might say that such a third option still has a lively existence today in the form of contemporary apologetics, but I would deny this interpretation. The aim of contemporary apologetics as far as I have seen (and I’ve been exposed to a fair bit of it) is entirely one-directional. It only seeks to use reason to show the truth of what a person already knows by faith. That’s not the sort of third option I’m talking about.
What is today often called “classical theism,” on the other hand, wishes to learn and affirm everything that we can about God, from faith and reason alike. In some places faith and reason overlap in their teachings, and in some areas they give distinct knowledge, but never do they clearly contradict one another, and any apparent contradiction will be treated, on this view, as representing a misunderstanding on one side or the other. The misunderstanding might be a misinterpretation of a scriptural text or traditional teaching, or it may be an imprecision in the process of reasoning. There are usually too many possible candidates for the cause of these sorts of misunderstandings, rather than too few. It is always easy to see many legitimate ways to synthesize an apparent conflict between reason and revelation.
On the account of classical theism, reason and revelation are mutually illuminating. Each gives us something we won’t have had without the other, and so each is clarified and elevated by associating with the other.
Religion gives to the philosophical theist a vocabulary of narratives and images and symbols. As humans, we all need that in one way or another, even the most cerebral of philosophers. There have been attempts in the past to create new, rational religions ex nihilo, but always without any real success. For some reason, what has worked best in history has always been embracing and interpreting and shaping an existing religious tradition. It is interesting that even Socrates, in the Republic, dreaming of constructing a new city according to whatever specifications he can think of, speaks only of editing the existing Greek mythology to be more appropriately pious, rather than of founding an entirely new religious system.
And philosophical theism in turn gives to religion a coherence and a rational foundation that dignifies the believer, because as a human the believer needs not just the great ancestral beliefs but also a connection to the timeless and universal truths that God has made knowable to reason. Ideally, a religion will be a path that is able to enchant person’s reason to higher and greater vistas of reality and understanding, rather than functioning as a solid roof that frustrates such attempts.
It is a fearful and angry fundamentalism that seals itself off from the influence of reason in the form of philosophical theism, and by doing so it does much damage, loses many of its youth, and finds itself untethered from anything but the competing interpretations of the text by its leaders, interpretations that can be various and mutable indeed. And philosophical theism that resolutely sets itself against religion as such, is doing needless harm to the fabric of society, to no good end, and possibly sealing itself off against a source of revealed truth.
In the modern world, faith and reason are set at odds, irrationally and unjustifiably. When we allow this to happen, we take away a great good from the religious person and from the reasonable person alike.