‘How many persons are there in the Godhead?’ asks the Shorter Catechism in Question 6.
The answer is, ‘There are three persons in the Godhead; the Father, the Son, and the Holy Ghost; and these three are one God, the same in substance, equal in power and glory.’
I’ve been reading through a collection of essays called, Retrieving Eternal Generation. One of the contributors is Chad Van Dixhoorn, with a chapter on the outputs of the Westminster Assembly. He gives the background to how the eventual wording of the Westminster Confession and Catechisms was arrived at.
“Cheynell had argued that the words ‘same’ and ‘equal’ were important. ‘Same’ emphasised unity, and ‘equal,’ in order to be intelligible, assumed diversity: ‘We do usually say that the Father, the Son and the Holy Ghost are equall in power, to note a distinction of persons; but when we speak strictly, we do not say that the power of the persons is equall, but we say the power of the persons is the same, to note the unity of their essence.’ The use of these terms, both here [in the Shorter Catechism] and in the Larger Catechism, and the insistence on the unity of substance created a crisp (now classic) Trinitarian summary.”
Which shows, perhaps, both that we are pushing language to its limits when we try to put in words who and what God is, and also that there is merit in having and learning and steeping ourselves in the most careful forms of words available.
C. Van Dixhoorn, ‘Post-Reformation Trinitarian Perspectives,’ in Retrieving Eternal Generation, ed. Fred Sanders and Scott R. Swain (Grand Rapids: Zondervan, 2017), 204.