Hell

To give further clarification on the "gnawing agony", the verse is Mark 9:44, it reads "Where their worm does not die". The Greek word for worm here is "skolex", it's literal meaning is a gnawing worm, but, when used literally it makes no sense. This is a metaphor, it is used to describe the eternal agony that these people will go through.
What should make the meaning crystal clear here is the fact that Jesus says,"their worm never dies" not "the worms never die", he uses the singular form for worm. Since when have you ever seen 1 worm eating a dead body. Then he uses a possessive word "auton" to give ownership to the worm, "their worm".
In this context it a more accurate translation would be "Where their gnawing agony never ends".

The quantity of references by Jesus to this place means that it is important that we know about it, believe in it and are warned of it's severe punishment and eternal nature. If we read his words in context and try to ascertain the meaning of what he is saying then there is only one conclusion that we can come to "Hell is very bad, don't take any chances of ending up there".

To say there is no hell is to basically call Jesus a liar, or to twist what he is saying in a way that insults the intelligence of the average reader.

God has no desire for anyone to end up in hell. Peter tells us, "His desire is for no one to perish but that all would repent from sin" and Ezekiel quotes God saying, "I take no pleasure in the death of the wicked.. I am pleased when they repent and live." Hell was not made for man, it was made for the fallen angels who knew God and openly rebelled trying to take over and rule creation.

We know that there are 2 kingdoms the Kingdom of God and the Kingdom of Satan(Matt. 12:26), you will belong to either one or the other. Those that reject the authority of God have only one other place to go, that is the Kingdom of Satan. Satan's Kingdom was this world, until Jesus came and took the keys of death and hell from him, upon his sacrifice for mankind. Satan and all of his works and authority are destined to be thrown into the lake of fire, as described by Revelation, and all that follow his rebellion angels and humans alike.

God is a perfect judge

We have a justice system here on earth. It is made up of man made laws that we as a society deem just, and judged by imperfect humans, because of this we have injustice at times due to the flaws of humanity. Innocent people are sentenced and the guilty are, at times, acquitted.

God's justice system has no such limitations, all acts are recorded and everyone is judged by what they have done. His laws are perfect, even if we don't understand them right now. His judgements are flawless, the guilty must always pay the price and the innocent are never wrongly sentenced.

So, why do people judge God for punishing criminals when they, as a society, do it also?
Do I call the citizens of the U.S. cruel and unjust because they lock people in prisons for life?

We know that when there are no laws or punishment that evil people take over, taking advantage of the weak and making life miserable for everyone. That is why we have our own justice system, where we take away people's freedom for life and even take their life in extreme cases. This is for our benefit as a community so we don't have people roaming around that will do harm to us or our families.

Yet, some would deny God that same right to have justice in this world that he has created. To protect his children from influences that would lead them on the wrong path and divert them from the purpose they were created for. The hypocrisy of those would be vindicated if they were to let the murderer, rapist, pedophiles, etc... go free in their own neighborhoods where their children were living. Not many are foolish enough to live in such a place.

Man has jail as the earthly punishment for people who break our law.
God has Hell as an eternal punishment for people who break his law.

Whatever country we are in we try to obey the law to avoid punishment, we have respect for the laws those people have chosen. So, why would people have contempt for the laws that God has chosen to set in place for the world that he created, when they normally follow man-made laws without question?

The imperfect man that now stands in judgement of God, will one day stand before a perfect God's judgement.

We will have Satan, who is called "the accuser of the brethren" on the prosecuting side and we will have Jesus who "is at God's right side speaking to him for us" as our defender.
For those who have not followed the path that Jesus instructed us to, will not have any defense. It will simply be the accusations of the sins that we have committed followed by God's judgement.

Man was created for a purpose, each person has a plan. You can live it according to God's design or you can please yourself and live however you choose.
When you live outside of God's will in this life you can't expect to live with him in the next.

The apex of pride is to say, "How dare God make rules for me to live by, this is my life and I will live it however I want." The humble person says, "God created me for a purpose, this is his universe and I will trust his wisdom and follow his plan."

This is what Jesus was talking about when he said, "If you cling to your life you will lose it, if you let it go you will save it."
To live life your own way is to throw away your very purpose. There is no greater fulfillment than to live your life the way that you were designed to.

Those who accept the path of righteousness that God has prescribed and are obedient to the commands he has given us have already entered the Kingdom of Heaven.

Why would God feel so strongly about sin and disobedience?

Like a parent, God gives us instruction, to protect ourselves and those around us from mental and physical harm.
Like a child, we don't understand the wisdom of many of the rules given us and we rebel because we think of them as unfair.

When we rebel against his commands we put ourselves and others in peril in many different ways. The frustration a parent feels about a self destructive child who puts themself and their siblings at risk is the same way that God would feel about the rebellious. He stills loves them, but, cannot allow them to be around the other siblings.

In the end the separation is eternal, Revelation tells us "Anyone whose name was not found written in the book of life was thrown into the lake of fire." and "But those who shrink from the faith, the unbelieving, the vile, the murderers, the sexually immoral, those who practice magic arts, the idolaters and all liars--they will be consigned to the fiery lake of burning sulfur.