Opinion by Salam al-Marayati, special to CNN

(CNN) - This week, Barak Barfi, the spokesman for slain American journalist Steven Sotloff’s family, joined many Muslims in exposing the hypocrisy and hollowness of groups like ISIS.

He challenged ISIS leader Abu Bakr al-Baghdadi to a debate that pits Islam’s theology of life against ISIS’ cult of death.

In doing so, Barfi cited verses in the Quran that shun murder even a 6-year-old could understand: "Fight in the cause of God those who fight you and do not transgress, God loves not the aggressors" (2:190).

This verse is about self-defense. It allows one to protect civilians by fighting combatants who attack first. It forbids aggression, which is a grave sin in Islam.

By citing this verse, Barfi challenged all extremists to a debate that would expose their bankrupt cult of death for the forgery it is.

Barfi also talked about mercy in Islam. Mercy is an essential attribute for Muslims. God delivered Prophet Mohammed to humanity to make us more merciful to one another.

ISIS is devoid of mercy and God assigns transgressors equal compensation for what they do on Earth; those who murder and pillage will only find hell’s darkness and pain in the hereafter.

The ideological fight against ISIS is not about reducing them to the true size of their moral feebleness. It's about humanity rallying together to isolate and eliminate this gang of thugs.

Steven Sotloff so “loved the Arab and the Islamic world,” Barfi said, that he courageously covered the story for American media. He committed his life and career to covering the suffering of Muslims at the hands of tyrants.

Most Americans who travel to the Middle East feel the same way. Aside from all the vitriol, political rhetoric and waving of religious banners, there is a desire by many Muslims to be heard and seen for what they are: human beings. ISIS distorts Islam and dehumanizes Muslims.

Ruslan Tsarni, the uncle of Tamerlan Tsarnaev, who committed the Boston Marathon bombing, said something similar to Barfi in explaining the motivation of violent extremism: The extremists are losers and full of hatred for those who were able to settle themselves.

ISIS is a group of lost souls who thrive in war-ravaged zones and rise from the ashes of despair.

Spare us, al-Baghdadi, the sermons and the bravado. They are nothing but tattoos cut into your soldiers with the blood of the innocent. You are not fostering martyrdom, but you are perpetuating criminality and corruption that has infested the region for centuries. You are a false prophet who has stained our sacred faith.

Our strongest weapon against ISIS is good theology against bad ideology. Understanding Islam along with the authentic sources of the Quran and the accepted traditions of the Prophet Mohammed is the antidote to violent extremism.

Our front lines are the mosques from where we repel this evil with good words meant to serve humanity. Our foot soldiers are the young men and women who want to lead this struggle. They will fight for us on the Internet and from the hallowed halls of institutions of learning and advancing civilization, of interdependence not separatism, of building bridges with other faiths, not destroying them.

That is the counternarrative that will help win the war against ISIS.

Barfi is also correct in rallying people to call the bluff of al-Baghdadi. Our only challenge is to overcome the fear ISIS uses to wield its influence.

To the families of Steven Sotloff and James Foley: We will remember the bravery of your sons, who exposed the savagery of tyranny and gave the people a platform for their voices to be heard and their suffering to be seen by the American people.

Salam al-Marayati is president of the Muslim Public Affairs Council. The views expressed in this column belong to him.