Most religions are actually quite useful if you take the actual teachings of them and don't take them literally.

You don't have to be a religious person to benefit from religion.

For example, the concept of hell or heaven is basically having a worse or better life in the future, based on what you do in the present.

So, if you sacrifice in the present, you'll probably be better off in the future (heaven). If you indulge yourself in the present, you'll probably be worse off in the future (hell). This applies to anything, for example you don't eat that extra ice cream today and you end up in a healthy range weight (heaven). You don't buy crap and instead invest money now, so that you end up wealthier in the future (heaven), etc.

There is a real spiritual Christianity which is spread organically by the self-sacrificing followers of Jesus Christ.

Then there is the religious tyranny that was spread throughout the dark ages by mad rulers who went through the country side burning pagans at the stake in the name of their own power and control. The torture fear and death was so widespread that the trauma still affects most European people's sub-conscience today.