First, just to clear the air, I used that phrase in response to a wall of text by Adam (neuroman9999), who used a longer variant of that concept buried in his text wall. Didn't originate with me.
According to Ambrose Bierce, noted USA journalist and satirist, taken from his work The Devil's Unabridged Dictionary:
Religion, n, the daughter of Hope and Fear, explaining to Ignorance the nature of the Unknowable
Faith, n, belief without evidence in what is told by one who speaks without knowledge, of things without parallel.
Religion has been called "the opiate of the masses" because it gives hope of a better afterlife to those who have no hope of their current existence ever getting better. In the sense that it can be a spiritual placebo for those whose lives are not happy, it can reduce their desire to create or indulge in various types of anarchy. To the extent that it offers some comfort to the masses to quiet them, religion will prevent crimes of violence.
Sadly, it has less effect on theft, robbery, burglary, and similar "deprivation of property" crimes because religion won't help most of the drug victims of the world. Their craving will consume all of their money and more than all of it, leading to desperation to obtain money to get the next "fix" - and by the time the person gets there, religion won't help. Their personal inner demons have already taken over inside them, far closer than any distant and aloof father figure.
The bigger problem comes in when religion starts down the "exclusion" road and names groups that are anathema to the current tenets of the religion. Hate crimes abound that were based on religious rhetoric.
For one egregious example, the way that Matthew Shepard was killed was brought on by religious anti-gay rhetoric. The murders of Drs. George Tiller and and David Gunn and at least nine others in the past two decades were caused by them being abortion providers. That was also indirectly brought on by anti-abortion rhetoric. We don't even need to discuss the atrocities in Kosovo in an "ethnic cleansing" brought about by religious differences but a lot of fatal assaults, arson, maiming, and other criminal atrocities can be laid at the feet of religion.
When religion introduces a "them vs. us" mentality, it invites conflict. The Wahabbi sect of Islam is not at all tolerant of the other sects and thus engages in bombings of other Muslims as well as their non-Muslim targets. The Branch Davidian cult and their "us vs. them" viewpoint led to the Waco tragedy. The Rev. Jim Jones down in Guyana used religion to induce people to drink Kool-Aid laced with cyanide.
I cannot say with any honesty that I feel religion is a force of good in the world. It induces people to believe in impossibilities when a hard dose of reality is what is really needed to have folks focus on what they must do to survive in the world that we have now. And that is to look within themselves for self-improvement, self-reliance, and self-motivation.