Catechisma

Q16. Did all mankind fall in Adam's first transgression?

The covenant being made with Adam, 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.

Scripture Proofs — King James Version

1

Romans 5:12

Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned.

1 Corinthians 15:21–22

For since by man came death, by man came also the resurrection of the dead. For as in Adam all die, even so in Christ shall all be made alive.