A. There are three persons in the Godhead; the Father, the Son, and the Holy Ghost [a]; and these three are one God, the same in substance, equal in power and glory. [b]

[a]. Matt. 3:16-17; 28:19; 2 Cor. 13:14; 1 Pet. 1:2

[b]. Ps. 45:6; John 1:1; 17:5; Acts 5:3-4; Rom. 9:5; Col. 2:9;

Jude 24-25

Source: https://www.apuritansmind.com/westminster-standards/shorter-catechism/