Yes, I understand where you are coming from. Though I claim to be Christian, I sincerely respect the Sikh religion and I think a lot of their prayers and worship of Waheguru are very powerful and true. And the Gurus are very noble and holy men. I do also find there is a lot of truth in the Christian religion also.
I agree that it is difficult and a mystery to understand the Trinity, God in three , Father, Son and Holy Spirit. I just go by what the Church teaches. The Trinity, as far as I understand is like you say, God, the Father and creator, Jesus, God the Son, and God The Holy Spirit . Jesus being the second part of the Trinity.
Confusing I know, but we don't worship three separate persons, God is one being. But with these three different attributes.
Jesus is God made flesh, was sent to us to reconcile the world back to God the Father and their creator, too free themselves of sin.
In St.John's Gospel, it says, that In the Beginning, was the word,(meaning the wisdom of God) and the word was made man.
If I may copy the text here .
In the beginning was the Word,
the word was with God,
and the word was God.
He was with God in the beginning.
Through Him all things came into being, not one thing came into being exept through him. .
What has come into being in him was life, life that shines in darkness, and darkness could not overpower it.
In the Old Testament , the Word or Wisdom of God is present with God before the world existed and reveals God to the world.
In John's Gospel, he sees the Word-Wisdom in the person of Jesus.
So my dear Sikh friends, the way I understand the Trinity, is similar to the way we are made, we are all made up of three things in one too, Body, Soul, and Spirit.
This is what we mean as three in one being. We are obviously not three different people, nor is God our Creator. He is one being with these three attributes.