The Christians have been struggling over this matter for centuries. I have yet to hear anyone explain just how a church that claims monotheism can still believe in three beings.
Simple.
THREE PERSONS IN ONE BEING.
The us government for instance, is represented by its executive, legislative and judicial branches. One does not suppose that the us has three governments, now, does anyone?
And if you want to push this analogy to its limit, the us is ONE body politic comprising 300 million persons.
One need not struggle very hard to grasp this concept.