Therefore I have always found it best to discuss the mystery of the Holy Trinity through aspects of life we experience and ponder.
Take time, for example: We experience time in the present moment, but in that present moment the past is summarized and the future is there in potential form.
What I mean is that the present moment contains all of the past. It is where the past has brought me to–not only my own past, but my whole ancestry and the whole of human history. The history train has brought us to this present moment and this present moment is the result and consequence of all that has gone before.
Furthermore, this present moment contains the seed of the future. What will be is held here in this present moment in a kind of potential reality. This is not to say that the future is pre-determined, but that every future possibility is contained in concentrated form in this present moment.
In one sense the past is totally unreal and the future is totally unreal, except that both are contained in this present moment.
The experience of time, therefore is a mystery that points to the mystery of the unity and trinity of the Holy Trinity. The past, present and future are three, but they are one in the present moment. Indeed, we can only experience the reality of the past as it lives in the present moment and the reality of the future as it exists in potential form in the present moment.
The church teaches that whatever is done by one person of the Holy Trinity is done by all three persons of the Holy Trinity. At the Annunciation, for example, the Father sent the Spirit to the Blessed Virgin and the Son consented to the incarnation. So in every action of one person of the Holy Trinity the three persons are involved.
As we experience the past and future in the present so our experience of Jesus is also an encounter with the Father and the Spirit.. The infilling of the Spirit is also an encounter with the Son and the Father. To know the presence of the Father is to know the Son and the Holy Spirit.
The present moment, therefore, is a window to eternity for eternity is one single, eternal moment. Here at this present moment, as you read this if you stop to contemplate–you are in touch with eternity.
The entire past is present here and so is the entire future. It is here. It is now.
It is not Other than this.
This is why the mystics say you will find God here and now or you will not find him at all.