It ought not to matter whether a Christian is a philosophical pluralist or (as the vast majority of intellectual Christians in post-Apostolic times have been) a monist.
(A monist regards ultimate reality as a unity, a pluralist as more-than-one.)
Christianity is not constrained by philosophy - whether Christian doctrine fits, or does not fit, into specific philosophical categories should be a matter of supreme indifference.
But in practice it does matter, and historically it has mattered a great deal - indeed philosophical disputes within Christianity have led to vicious, tragic, stupid, futile and irreversible schisms - such as the Monophysite controversy in the fifth century of the Eastern Roman Empire.
Philosophical disputes have been the bane of Christianity.
But the fact is that my opening statement is itself a pluralist statement, and a monist cannot (qua monism) regard pluralism as a matter of secondary importance.
To a monist, pluralism is an error; and any other monism than his own monism is also an error - and he cannot have a sense of proportion or perspective about the consequences of such a perceived-error: if you regard reality as specific unity and other people say it is a different unity, or else not a unity at all, then the consequences of such disagreement seem to be almost infinite in their scope.
So although the pluralist may see himself as a healer and conciliator of philosophical disputes, he will probably find himself under concerted attack from all monists of every stripe who - even if they agree on nothing else - agree on the falsity of pluralism!
And that, indeed, is precisely how I conceptualize my own situation as a Christian pluralist!
From my perspective, I regard Christian monists as occupying a variety of real Christian positions; but from the perspective of the various monists, they regard me as not being a Christian at all.
I think such anti-pluralist monists are wrong, objectively wrong, in rejecting pluralism as a Christian possibility - because they are in fact (despite whatever they may suppose they are doing) asserting that the philosophical principle of unity should structure Christianity.
Christianity should rule philosophy, rather than vice versa - and (given human limitations and the incompleteness of all rational systems) this will very likely mean that to get the Christianity right entails messing-up the philosophy: so be it.
But this is an analytic point which many Christian monists apparently cannot accept, nor even comprehend - since they are rooted in their monism.
To the primary monist, pluralism is necessarily incomplete or incompetent; or most worryingly dishonest - on the basis that pluralists 'must be' some kind of covert monist who is concealing his monism for strategic reasons.
Also, to the Christian who is a primary monist the paradoxical doctrine of the Holy Trinity being both three and one is the core of Christianity - something upon which all else depends.
Because for Christianity to be acceptable to the monist, entails the absolute unity of God - while to be a Christian entails the divinity of Christ.
(And the Holy Ghost as well - but historically the difficulty has been Christ - because Old Testament Hebrew monists had no problem about conceptualizing the Holy Ghost as an aspect of one God.)
Hence the paradoxical/ incoherent definition of the Holy Trinity as absolutely one AND absolutely more-than-one is a principle that must be asserted as a definitional dogma requiring public assent: an incomprehensible 'truth' to which all monists who are Christians must submit.
Perhaps the definition or comprehension of the Holy Trinity marks a cleavage point among monists:
between on the one hand monists who are Christians (monism comes first) - and who insist on the paradoxical definition of the Trinity, and place it at the centre or forefront of Christianity - and who will in practice make paradoxical Trinitarianism definitional of Christianity...
and Christians who are monists, who put Christianity first and are able to tolerate imperfect monism - who are prepared to accept that there is an intractable problem with applying monism to the Trinity; and who will therefore tend to down-play and work-around the paradoxical definition of the Trinity - will tend to regard it as a mystery rather than a higher-logic; and will not exclude from definitions of Christianity those persons or denominations who cannot or will not make public assent to paradoxical Trinitarianism.
So, in theory, by putting Christianity first and accepting imperfect philosophy, Christians who are monists can regard philosophical pluralists as being also Christians; while monists who are Christians will exclude philosophical pluralists from their definition of Christianity.
In other words, the cleavage shows-up in the way that Christianity is recognized, defined and demarcated: monists who are Christians will define Christianity in terms of philosophical concepts - and that is one way of identifying them.