Westminster Shorter Catechism

Q16

Did all mankind fall in Adam’s first transgression?

The covenant being made with Adam40, 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 transgression41.
Doctrine
Ch. VI Of the Fall of Man, of Sin, and of the Punishment thereof

Scripture Proofs

40
Genesis 2:16-17James 2:10
41
Romans 5:12-211 Corinthians 15:22