The acceptance of the imaginary and fantasy as reality and basing ones own reality on that.

The religious indoctrination and abuse of children.

Too often, religion is a pilar of tyranny.
Too often, tyrants rely on religion to oppress people.

Guilt

ISLAM: the last and only religion. Based in this fascistic premise is all the darkness it has wrought in the 1400 years of violent expansion.

Human Sacrifice to the 'Gods'.

Religious literalism.

Using the fear of hell to control people.

The practice of continuous warfare. The world can eliminate war by eliminating religion. Look at all the wars that have occurred because of religion. Frightening.

Probably the idea of Original Sin. It's led to a lot of tragedy and neurosis (which did give us Woody Allen).

Simple!!!

All of the religions are dangerous, some have mellowed only to return to their death cult status with the next know-it all generation!!!

Submit to Authority-666 pay taxes Masonic lodge secret religion racist devil worshippers. Nothing being done to provide free brick homes for everyone on Earth built by true masons: free from mortgage free from rent free from taxation free from governmental terrorism and free from religious oppression.

Promotion of the ‘us vs. them’ mentality.. We apparently have a tribal instinct; the good advocate we ditch it - the religious encourage it.

The brainwashing

The attempt of supremacy over other creeds. The Crusades, the Holy Inquisition, the nowadays Religious Police in certain Muslim countries. Probably there will be more to point out.

Its anti-education, not just in the sense of its direct disputes with science, secular philosophy and honest reportage, which are bad enough. But as much anything else, because it wastes time and resources which could be spent on real education, on the pedaling of pseudo-education.

In other words every time someone spends an hour learning a religious text, it is an hour lost that they could have spent on something of far greater value. Especially so if they are deluded by it into thinking that what they are receiving is "education".

Religion. It teachs people to turn their life over to an invisible skydaddy and not take responsibility. It's taken over politics.

The nonsense that "we are all sinners" and must be forgiven

There are so many gods how to choose?

Climate Change denial via religion. "Any planetary changes are Gods will, and its all gonna burn in the end before he remakes it, SFW about global warming?"
As a dogmatic ideology amongst the believers.

Impossible feat with so many religious sects each with it's own abomination

FGM

One true god is sort of like one true Scotsman. I do not debate (at least not long and drawn out) because it proves nothing. I'm still surprised by the comment of the idiot in You Tube who wanted me to "give him proof" of why I no longer believe. I do not have to have proof for changing my mind due to lack of evidence. However, if you pray while standing on one leg and have your tongue in your cheek, then hop around a bit and try not to fart, maybe god will bless you. If he did not you still have some sin in your life, or it is because of something that you father did.

The whole of it.