CapitalistCatholic is correct. If God were just putting on three faces or filling three roles, that would be “modalism.”
spiritflower9 – The Holy Trinity is a complicated topic. It’s a mystery. We know it’s true and we contemplate it, but no human being can fully comprehend it. So we tend to use partially true pictures and examples, like the clover or the lightbulb. None of these pictures will fit exactly; they are just supposed to give you something like the idea.
God always existed. God created time and space; they didn’t exist until He created them. He dwells in eternity, outside of space and time, although He is present everywhere within space and time.
God is love. Love doesn’t exist unless there is someone to love and someone to be loved. And so, God was always three “Persons” - Father, Son, and Holy Spirit. These three Persons are one God.
The “Persons” are not… quite… the same thing as we normally mean, when we say “person.” It’s the translation of a Greek theology term, “hypostasis.” But they are distinct from each other, as well as being perfectly in union with each other. Nope, humans don’t really work that way. Even angels don’t work that way. Only God does.
It really is hard to know what to say, so as not to mislead you. Probably the best thing to do is to look at the different Bible verses that are related to the Trinity, and then see how the teaching arose from Jesus’ teaching and from apostolic teaching, as well as by studying the implications of all the verses.
Here’s the late Fr. Hardon’s short definition of the Holy Trinity:
God, who is one and unique in his infinite substance or nature, is three really distinct persons, the Father, Son, and Holy Spirit. The one and only God Is the Father, the Son, and the Holy Spirit. Yet God the Father is not God the Son, but generates the Son eternally, as the Son is eternally begotten. The Holy Spirit is neither the Father nor the Son, but a distinct person having his divine nature from the Father and the Son by eternal procession. The three divine persons are co-equal, co-eternal, and consubstantial and deserve co-equal glory and adoration.