Pelagius (ca. AD 354 – ca. AD 420/440 ), the founder of Pelagianism, the denial of the doctrine of original sin.

The Holy Bible says,

Surely I was sinful at birth, sinful from the time my mother conceived me. (Psalm 51:5).

...For there is no one who does not sin. (1 King 8:44).

Who can say, "I have kept my heart pure; I am clean and without sin?" (Proverbs 20:9).