The Greek word for hell, gehenna, originally referred to a valley outside Jerusalem where some of the kings of Judah worshiped idols and performed human sacrifice by fire (2 Chronicles 28:3; 33:6; Jeremiah 7:31; 32:35). The site was eventually destroyed by King Josiah (2 Kings 23:10).In the New Testament, gehenna refers to the place of eternal punishment by God.
In this and other related verses Jesus uses hyperbole to reinforce the the potential consequences of sin. It's like Jesus is saying that the possibility of going to hell is of eternal significance, so do whatever it takes to avoid it--don't go to hell!
The graphic images described by Jesus--gouging out your eye or cutting off your arm--call for radical separation from sin.
But what makes one sin more egregious than another, however, is really just a matter of degree, because all forms of sin and misbehavior are a result of the condition of the heart. Murder is the result of uncontrolled anger; adultery results from unrestrained lust.
So it is not murder but anger, not adultery but lust that violates God’s righteous standard.
It's what is on the inside of a person that is integral to one's spiritual formation and one's eternal destination.
Our eternal lives are a matter of the heart and so the real issue with Jesus is not what kind of person you are, but what kind of person you are becoming.
And, according to Jesus, the condition of your heart has eternal consequences. Jesus doesn't want you to go to hell!
"You can enter God’s Kingdom only through the narrow gate. The highway
to hell is broad, and its gate is wide for the many who choose that way." (Matthew 7:13, NLT)
