Trinity
2 of the 6 encyclopedias on this shelf carry an entry for Trinity. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
a term used to express the doctrine of Three Persons in one Godhead, which is held alike by the Roman, Greek, and Anglican Churches, and by the greater number of Nonconformist communions. It is indicated in the Apostles' Creed, stated more explicitly in the Nicene Creed, and set out at length in the Athanasian Creed. The First Article of the Church of England states the doctrine in terms that would be accepted by sister churches, and by orthodox dissenters generally: "There is but One Living and True God. And in Unity of this Godhead there be Three Persons, of one substance, power and eternity; the Father, the Word, and the Holy Ghost." Protestant theologians deduce the doctrine of the Trinity from texts in which (a) the Unity of God is affirmed (Deut. vi: 4; Isa. xliv: 6; Mark xii: 29-32; Eph. iv: 6); (b) the Divinity of Christ is shown from the fulfillment of Messianic prophecies, or directly affirmed (I Pet. ii: 7, 8; Isa. viii: 13, 14; John xii: 41; Isa. vi: 1; II Pet. iii: 18; Isa. xliii: 11; Rev. xxii: 13; Isa. xliv: 6; Matt. xi: 10; Mal. iii: 1; I Cor. x: 9; Ps. lxxviii: 18 and xcv: 9; John iii: 29; Isa. liv: 5; John i: 1, xiv: 11, xx: 28; Rom. ix: 5; III Cor. v: 19, 20; Col. ii: 8, 9; II Pet. i: 2; I John v: 20); and (c) the Divinity of the Holy Ghost is affirmed (Matt. ix: 38; Acts xiii: 4; John vi: 45; I Cor. ii: 13; John xiv: 17; I Cor. xiv: 25; Ezek. viii: 1-3; Matt. xii: 28; Acts v: 9; I Cor. ii: 11; II Cor. i: 3). The word "Trinity" is not found in the Scriptures, and is said to have been first used by Theophilus, Bishop of Antioch, in the 2d century.
Aiton's Encyclopedia (1910)
three in one, a trio. In theology, the unity of three persons, Father, Son, and Holy Spirit, in one Godhead. The doctrine of the trinity is a distinguishing tenet of the Greek, the Roman Catholic, and, if we except the Unitarian, nearly all Protestant churches. In recognition of the doctrine of the trinity, the number three is a favorite in Christian architecture. Three doorways or portals, three aisles, three-headed windows, the pattern of trefoil or three leaves in tracery, and many other similar uses of three have reference to the trinity. The three-petaled lily and the three-foliate clover leaf were for this reason favorite patterns in Christian ornamentation. See Arianism ; Unitarianism; Nice
What Has Changed in the Last Century
The doctrine described here has not moved: the Nicene and Athanasian formulations Collier's cited in 1921, and the Church of England's First Article it quoted, remain in force in the Roman Catholic, Orthodox, Anglican and most Protestant churches. What has shifted is the setting. Trinitarian belief became the explicit entrance requirement of organised ecumenism, the World Council of Churches (founded 1948) confessing God as "Father, Son and Holy Spirit"; the ancient Filioque quarrel between East and West is now argued in dialogue rather than schismatic polemic; and Aiton's 1910 exception, the Unitarians, merged with the Universalists in 1961 into a body that no longer describes itself as Christian at all. On the historical detail, scholars credit Theophilus of Antioch with the Greek trias, as Collier's says, but the Latin trinitas is attributed to Tertullian around 200 AD, and the old proof-text of 1 John 5:7 (the "Johannine Comma") is absent from modern critical Bibles as a late addition.
Written for this edition, 2026.