A difficult sentence: “The inclination of a person’s heart is evil from his youth” (Gen. 8:21).
It doesn’t mean that one is born sinful and can’t do anything about it.
The Hebrew min-urav is not “from his youth” but “because of his youth”.
It is moral immaturity that makes it difficult to control the temptation to sin. The more one matures morally the more he is able to manage himself and his deeds.