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Has Religion Done More Harm Than Good?

Crusading armies massacred civilians. Basil built a city for the sick, Julian envied Christian charity, and Wilberforce fought slavery. Matthew 7 judges fruit.

Updated 2026-10-18 · Atheism

Author Paul Ambrose

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Religion is not one actor with one ledger. People have killed under religious banners, and people have spent their lives against the slave trade and for the sick in the name of Christ. Matthew 7:16–20 Matthew 7:16–20 · King James Version^7:16 Ye shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles? ^7:17 Even so every good tree bringeth forth good fruit; but a corrupt tree bringeth forth evil fruit. ^7:18 A good tree cannot bring forth evil fruit, neither can a corrupt tree bring forth good fruit. ^7:19 Every tree that bringeth not forth good fruit is hewn down, and cast into the fire. ^7:20 Wherefore by their fruits ye shall know them.Matthew 7:16–20 · King James VersionOpen the Source says a tree is known by its fruit. The question “more harm than good” asks for a single sum that the record does not supply.

Key Points

The strongest form of the charge is Christopher Hitchens’s 2007 subtitle, How Religion Poisons Everything.
Were the Crusades Justified? records massacres in the Rhineland in 1096 and at Jerusalem in 1099, and the sack of Christian Constantinople in 1204, which Innocent III condemned.
Gregory of Nazianzus describes Basil’s fourth-century “new city” for the poor and the sick. The emperor Julian complained in 362 that “the impious Galilaeans support not only their own poor but ours as well.”
William Wilberforce, in 1807, numbered the mitigation and then the abolition of slavery “among the peculiar glories of Christianity.”
Matthew 7:21–23 Matthew 7:21–23 · King James Version^7:21 Not every one that saith unto me, Lord, Lord, shall enter into the kingdom of heaven; but he that doeth the will of my Father which is in heaven. ^7:22 Many will say to me in that day, Lord, Lord, have we not prophesied in thy name? and in thy name have cast out devils? and in thy name done many wonderful works? ^7:23 And then will I profess unto them, I never knew you: depart from me, ye that work iniquity.Matthew 7:21–23 · King James VersionOpen the Source says not everyone who says “Lord, Lord” enters the kingdom. The Christian claim already refuses to bless every act done in the name of Jesus.

What Is the Case Against Religion?

The charge has a book title. Christopher Hitchens published God Is Not Great: How Religion Poisons Everything in 2007, and it was a National Book Award finalist that year. The subtitle is the claim in its strongest form: not that religion sometimes does harm, but that it spoils whatever it touches. What Do Atheists Argue Against God? covers the separate arguments from evidence and from suffering. This page takes the historical charge.

The question needs its terms fixed. “Religion” here is not every belief in God, but particular churches and believers acting in history. “Harm” and “good” are judged by a standard both sides already use: killing the innocent is evil, and feeding the poor and nursing the sick is good. Julian, Gregory, and Wilberforce all wrote with that standard in view.

The Christian record has real entries on that side. Were the Crusades Justified? follows Urban II, the Rhineland massacres of 1096, the taking of Jerusalem in 1099, and the sack of Constantinople in 1204. Did Christianity Spread by the Sword? is the separate question of baptism by force. Those pages do not call the killings a side note. They also quote Matthew 26:52 Matthew 26:52 · King James VersionThen said Jesus unto him, Put up again thy sword into his place: for all they that take the sword shall perish with the sword.Matthew 26:52 · King James VersionOpen the Source, where Jesus tells Peter to put the sword back, because all who take the sword shall perish by the sword. The armies broke the command of the one they named.

What Good Has Religion Done?

Early Christian care for the sick is described by people who saw it. Gregory of Nazianzus, in his funeral oration for Basil of Caesarea, wrote of the foundation Basil built outside the city:

Go forth a little way from the city, and behold the new city, the storehouse of piety, the common treasury of the wealthy, in which the superfluities of their wealth, aye, and even their necessaries, are stored, in consequence of his exhortations

Section 63 says it was a place “where disease is regarded in a religious light,” and that Basil’s care “was for the sick, and the relief of their wounds, and the imitation of Christ, by cleansing leprosy, not by a word, but in deed.”

An enemy of the church said the same. The emperor Julian, who tried to restore the old gods, wrote to Arsacius, the high priest of Galatia, in Letter 22. He told him to set up hostels and distribute grain. Then he gave the reason: “For it is disgraceful that, when no Jew ever has to beg, and the impious Galilaeans support not only their own poor but ours as well, all men see that our people lack aid from us.” He names “their benevolence to strangers” among the things that had “done most to increase atheism,” his word for the Christian faith that refused his gods.

What About Slavery?

Slavery is the hardest test. William Wilberforce, in his Letter on the Abolition of the Slave Trade A Letter on the Abolition of the Slave Trade · William Wilberforce, 1807to have first mitigated the evils of slavery, and at length in a great degree to have abolished the institution itself, have been numbered among the peculiar glories of Christianity.A Letter on the Abolition of the Slave Trade · William Wilberforce, 1807Open the Source of 1807, answered the claim that Africans were “an inferior race of beings” as “a position so shameless, and so expressly contradicted by the Holy Scriptures.” He wrote:

to have first mitigated the evils of slavery, and at length in a great degree to have abolished the institution itself, have been numbered among the peculiar glories of Christianity

A Letter on the Abolition of the Slave Trade · William Wilberforce, 1807

The slaveholders also quoted the Bible. Ephesians 6:5–9: Does “Slaves, Obey Your Masters” Support Slavery? and Does the Bible Support Slavery? quote the texts both sides used. That belongs in the answer too.

Why One Score Fails

A list of religious wars, of the kind Were the Crusades Justified? has to answer, treats every killing in a religious century as the religion’s fruit. A list of secular regimes treats every twentieth-century crime as proof that unbelief is worse. Both pick the bodies that help the speech. The documents above do not add up to a total, and no honest total is on offer. What they show is that the same faith produced Basil’s hospital and the sack of Jerusalem, and that its own texts condemn the second.

Matthew 7:15–20 Matthew 7:15–20 · King James Version^7:15 Beware of false prophets, which come to you in sheep’s clothing, but inwardly they are ravening wolves. ^7:16 Ye shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles? ^7:17 Even so every good tree bringeth forth good fruit; but a corrupt tree bringeth forth evil fruit. ^7:18 A good tree cannot bring forth evil fruit, neither can a corrupt tree bring forth good fruit. ^7:19 Every tree that bringeth not forth good fruit is hewn down, and cast into the fire. ^7:20 Wherefore by their fruits ye shall know them.Matthew 7:15–20 · King James VersionOpen the Source says you will know them by their fruits. The next verses say many will say “Lord, Lord” and point at works done in that name, and Jesus will say he never knew them. James 1:27 James 1:27 · King James VersionPure religion and undefiled before God and the Father is this, To visit the fatherless and widows in their affliction, and to keep himself unspotted from the world.James 1:27 · King James VersionOpen the Source defines pure religion as visiting orphans and widows in their affliction. Basil’s new city and Julian’s complaint are that verse obeyed. The Crusade massacres are Matthew 26:52 disobeyed. The Christian confession does not defend every army that carried a cross. It says Jesus is God, that he refused the sword in Gethsemane, and that the fruit he names is obedience to him.

Frequently Asked Questions

Has Religion Caused Most Wars?

A percentage of wars caused by religion depends on how a war is classified, and no count is cited here because none was checked against its source. The Crusades were armed pilgrimages called by popes, and they included massacres. The command Jesus gave Peter is the standard those wars are judged by.

Does the Size of a Religion Settle the Question?

No. Pew’s report of 9 June 2025 still has Christianity as the largest group in 2020, and Islam as the fastest-growing over the previous decade. A census measures a population, not its fruit. Is Islam the Fastest-Growing Religion, and Does That Prove It Is True? takes up the same mistake for a rising count.

Keep Reading

References

Gospel of Matthew, 7:13–23; 26:52 Matthew 7:13–23 · King James Version^7:13 Enter ye in at the strait gate: for wide is the gate, and broad is the way, that leadeth to destruction, and many there be which go in thereat: ^7:14 Because strait is the gate, and narrow is the way, which leadeth unto life, and few there be that find it. ^7:15 Beware of false prophets, which come to you in sheep’s clothing, but inwardly they are ravening wolves. ^7:16 Ye shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles? ^7:17 Even so every good tree bringeth forth good fruit; but a corrupt tree bringeth forth evil fruit. ^7:18 A good tree cannot bring forth evil fruit, neither can a corrupt tree bring forth good fruit. ^7:19 Every tree that bringeth not forth good fruit is hewn down, and cast into the fire. ^7:20 Wherefore by their fruits ye shall know them. ^7:21 Not every one that saith unto me, Lord, Lord, shall enter into the kingdom of heaven; but he that doeth the will of my Father which is in heaven. ^7:22 Many will say to me in that day, Lord, Lord, have we not prophesied in thy name? and in thy name have cast out devils? and in thy name done many wonderful works? ^7:23 And then will I profess unto them, I never knew you: depart from me, ye that work iniquity.Matthew 7:13–23 · King James VersionOpen the Source. King James Version
Letter of James, 1:27 James 1:27 · King James VersionPure religion and undefiled before God and the Father is this, To visit the fatherless and widows in their affliction, and to keep himself unspotted from the world.James 1:27 · King James VersionOpen the Source. King James Version
Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020, Conrad Hackett and others, 9 June 2025 (Christians remained the world’s largest religious group in that count. Size is not a moral verdict.)
William Wilberforce, A Letter on the Abolition of the Slave Trade, London, 1807, scan A Letter on the Abolition of the Slave Trade · William Wilberforce, 1807to have first mitigated the evils of slavery, and at length in a great degree to have abolished the institution itself, have been numbered among the peculiar glories of Christianity.A Letter on the Abolition of the Slave Trade · William Wilberforce, 1807Open the Source (The mitigation and abolition of slavery numbered among the peculiar glories of Christianity.)
Gregory of Nazianzus, Oration 43, Funeral Oration on Basil the Great, Section 63 (New Advent, Nicene and Post-Nicene Fathers translation. Basil’s new city for the poor and the sick.)
Julian, Letter 22, To Arsacius, High-priest of Galatia, Wright translation, 362 (The emperor says the Galileans support their own poor and the pagans’ poor as well.)
Christopher Hitchens, God Is Not Great: How Religion Poisons Everything, Twelve, 2007; National Book Award finalist entry (The book’s subtitle states the atheist case in its strongest form.)