As I have said before, I am by nature a pluralist - which is why I have gravitated to Mormon theology (my take on Mormon theology is that it is Christian pluralism).
One way of thinking about this is the infinite regress problem, which children often discover for themselves.
What causes this? Answer given: this is caused by that. Yes but what causes that, and then what causes that... and so on, and on... forever?
An infinite regress?
Well then no, not forever.
The only thing that can stop the regress is an uncaused cause - something which makes other things happen but not in response to other things happening.
Something which is an origin of action.
(This is also something with free will. Free will is an uncaused cause.)
So... everything that happens can be traced back to an uncaused cause.
But how many uncaused causes? - One, or more than one; one or many? Monism or pluralism?
To answer the question one uncaused cause, versus many uncaused causes, is apparently a matter of intuition, a metaphysical assumption; undecidable on the basis of evidence.
And undecidable on the basis of Christian revelation.
Most Christians are monists and trace all causes back to one God.
This leads to a problem when considering Jesus and the Holy Trinity in general. Is Jesus an uncaused cause, or not? If so, then God is two; if not then Jesus is just an aspect of God: inessential. This problem has not been solved by monism (only obscured by sleight of language).
Monism also leads to the problem that humans have no free will, since all causes are traced back to God. Insofar that Jesus is essential to our salvation, and insofar as free will is essential to Christianity, then monism is deficient.
Pluralists like me believe there are more-than-one/ many uncaused causes; so Jesus and the Trinity is not a problem - Father, sona and Holy ghost are all uncaused causes; and free will is not a problem (since each humans is an uncaused cause).
But it is messy! To a monist it is unacceptably messy - it just can't be true!
But a pluralist feels this is intuitively right; that reality is many not one, that there are many uncaused causes interacting, will be forever, and always have been...