“The Eternal Being reveals Himself in His triune existence even more richly and vitally than in His attributes. It is in this holy trinity that each attribute of His Being comes into its own, so to speak, gets its fullest content, and takes on its profoundest meaning. It is only when we contemplate this trinity that we know who and what God is. Only then do we know, moreover, who God is and what He is for lost man-kind. We can know this only when we know and confess Him as the Triune God of the Covenant, as Father, Son, and Holy Spirit.” (Herman Bavinck)
For more on this subject, please visit the Systematic Theology page.