The Holy Trinity is the absolute ground and grammar of all epistemology, theology, and worship; so says our thesis one from chapter fifteen in our volume one Evangelical Calvinism book. Torrance beautifully illustrates this in what he writes below:
While the Lord Jesus Christ constitutes the pivotal centre of our knowledge of God, God’s distinctive self-revelation as Holy Trinity, One Being, Three Persons, creates the overall framework within which all Christian theology is to be formulated. Understandably, therefore, the doctrine of the Holy Trinity has been called the innermost heart of Christian faith and worship, the central dogma of classical theology, the fundamental grammar of our knowledge of God. It belongs to the Gospel of God’s saving and redeeming love in Jesus Christ who died for us and rose again and has given us the Holy Spirit who has shed the love of God abroad in our hearts. The doctrine of the Trinity enshrines the essentially Christian conception of God: it constitutes the ultimate evangelical expression of the Grace of the Lord Jesus Christ who though he was rich for our sakes became poor that we through his poverty might become rich, of the Love of God who did not spare his own Son but delivered him up for us all, for it is in that personal sacrifice of the Father to which everything in the Gospel goes back, and of the Communion of the Holy Spirit through whom and in whom we are made to participate in the eternal Communion of the Father and the Son and are united with one another in the redeemed life of the people of God. Through Christ and in the Spirit God has communicated himself to us in such a wonderful way that we may really know him and have communion with in his inner life as Father, Son and Holy Spirit.
 Thomas F. Torrance, The Christian Doctrine of God: One Being Three Persons, 2.