The Trinity is one of the most difficult realities to comprehend but it might be a helpful start to recognize the distinction between a “being” and a “person”.
God is one being (the one and only *divine *being). This divine being exists as three persons (Father, Son, and Holy Spirit). This is unusual to us because each *human *being is only one person and it might seem that every being has to be one person: one being = one person.
But that’s simply not always the case. For example, a dog is a being but is not a person. A tree is a being but is not a person. In these cases, one being = zero persons. On the other hand, an angel is a being and is a person. In their case, angelic beings are similar to human beings: one being = one person.
Once it is recognized that not every being is always exactly one person it might be easier to grasp God’s unique reality, the Trinity: one being = three persons.
I hope this is a helpful start.
