[Mostly Harmless]

Religion is like Government: It's basis can be a beautiful addition to yr life, but anything that is beautiful and helpful can just as easily become overbearing and ultimately fucked up institutions by humans.
The purpose of a good Government is to allow it's people to thrive and to protect their basic rights. But even the best government in the wrong hands can become a corruption and a pain for its people. I think most would agree this is the case of the United States, which at its base principles is a great system, but in the hands of our present rulers it really angers the American people and suffocates the rest of the world. It's not the fact that we have a government, it's the shitholes who run it.

A good religion brings you peace of mind and can potentially offer insight to the human condition to help you cope with the bullshit we deal with (disease, insatiable lusts, class inequality, etc)
Christianity is a good example
Because this religion has for the most part been hijacked and fucked up by total assholes who indoctrinated crazy shit to control peasants (Catholicism) or attract converts (the Protestant donominations and to a lesser extent the Catholics) or whatnot doesn't mean that Christianity's base is an evil institution. If we accept even somewhat the Gospels authenticity, Jesus had followers and obviously considered himself a religious leader of some sort "Before Abraham, I AM" John 8:58.
But again, if we even vaguely accept the Gospels, Jesus didn't walk around thinking "If I can win over the illiterate peasants with this gibberjabber, I can milk them for all their worth and live like a king, and logic behind the Caste System will never be questioned! MUHAHAHAHA!" Christianity has been accused of this behavior, and rightly so due to the popes and some those who took charge the movement in much later generations. But the base religion itself which is bursting with love, reason, and passion for humanity* isn't a shallow, corrupt institution engineered to keep the workingman down. Jesus was just some poor carpenter who thought evil could be eradicated if people returned everything, even hate, with love.
Any religion can become a curse to the lives of its followers if shitholes run it.

*Chock full of humanity:
"A new commandment I give to you, that you love on another, even as I have loved you...." John 13:34
"But I say to you, love your enemies and pray for those who persecute you..." Matt 5:44
"Let him who is without sin among you be the first to throw a stone at her."
John 8:7
The entire Beatitudes, already listed by Rob Instigator.
"If we condemn others, it is because we shun knowing ourselves." -St. Seraphim of Sarov (I know I've been ranting on the purity of the base religion, but I couldn't help but include this gem of a quote from this gem of a saint)
I've cited enough verses for the reasons of this post, but all the Gospels are filled with this.