Q. 16. Did all mankind fall in Adam’s first transgression?

A. The covenant being made with Adam [a], not only for himself, but for his posterity; all mankind, descending from him by ordinary generation, sinned in him, and fell with him, in his first transgression [b].

[a]. Gen. 2:16-17; Jas. 2:10

[b]. Rom. 5:12-21; 1 Cor. 15:22


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