'Sin' in the Bible

But whoever blasphemes against the Holy Spirit does not have forgiveness {forever}, but is guilty of [an] eternal sin"--

"And whoever causes one of these little ones who believe in me to sin, it is better for him if instead {a large millstone} is placed around his neck and he is thrown into the sea.

And if your hand causes you to sin, cut it off! It is better [for] you to enter into life crippled than, having two hands, to go into hell--into the unquenchable fire!

And if your foot causes you to sin, cut it off! It is better [for] you to enter into life lame than, having two feet, to be thrown into hell!

And if your eye causes you to sin, tear it out! It is better [for] you to enter into the kingdom of God with one eye than, having two eyes, to be thrown into hell,