As a kid I just couldn't wrap my head around the idea of salvation. It wasn't a big deal, I just accepted what they taught me at home, in church and at school, and assumed that when I'm older and wiser, I'll finally understand.
This approach worked out for many other things, like understanding how sex actually works or finally learning what “money laundering” means (my parents never managed to explain either to me). When it comes to salvation, though... I might be an educated adult with a solid dose of religious indoctrination in the past, but I still cannot understand how can any rational person believe in salvation.
It just doesn't make sense. None at all, from any perspective. It's just bullshit.
In the beginning there was sin
Let's start at the beginning: what do we even need salvation from? Well, from sin, obviously. Because we are all sinful, of course. It's all because Adam & Eve. Because they did something wrong – without even knowing it was wrong.
You know, like when a child says “fuck” without even knowing what it means, and instead of explaining them that it's a nasty word and they shouldn't repeat that, you get angry at them, throw them out of your house make them beg you for ever and ever to forgive them for that one “fuck”.
Save from what?
It seems so obvious to Christians that humans need “salvation”. But salvation from what? What's gonna happen if no one “saves” us?
Whatever the punishment is, it comes from god. Ex definitione. Dude's supposed to be all-powerful and the source of everything that happens in the universe (yes, even evil, see: Isaiah 45, 7).
Is god saving us from himself?
Apparently, I'm more powerful than god in one manner: I am able to forgive someone without requiring a human sacrifice.
Why the hell would an all-powerful, benevolent god come up with such a crazy plan, if he could just forgive?
I think we can all agree that there's no greater sacrifice than sacrificing your life. From an atheistic perspective it's literally all we can give. Whatever you owned, whatever you planned to do, whatever you craved for – it's all useless if you're dead.
Even Christians, who believe in life after death, and who claim that one is the real life, while our time here on Earth is basically worthless, they still don't want to leave this planet too early. Even Jesus himself said that “Greater love has no one than this: to lay down one’s life for one’s friends” (John 15, 13).
And Jesus's sacrifice is supposed to be the greatest ever. So powerful that it can redress all the wrongdoings in the entire history of humankind! It needs to be huge! And it supposedly is: not only is it someone offering their live, but also this someone is an all powerful god. Can't get bigger than that, can it?
Except it can get smaller. You know, when you come back to life after three days. Sure, all the tortures you've suffered were awful and everything, but in the end you have your life back, right? Also, you are supposed to be a Trinity. Have you really been dead for those three days, if two thirds of you we fine and living all along?
So as big as your sacrifice might have been – was it really the greatest one ever? Was it so huge that it can redeem every single murder, rape, theft and fraud in the entire history?
Pay a “debt” to whom?
Jesus's sacrifice is often described as “paying off a debt” (for instance in the Exsultet). Who paid whom with what, may I ask? God paid god with god's life? That makes perfect sense!
When my husband jokingly demands some money from me for something, I joke back, saying I'll transfer it to his account. You see, the joke is: we have a shared bank account.
How is that different from god paying himself off?
Serving someone else's time?
Would it be moral (and legal), if I decided to go to jail, as an innocent person, in place of some rightfully convicted criminal?
Is the world going to be a better place, if I sacrifice myself so that a person who should suffer the consequences for their terrible actions goes free?
Would any judge allow it, if I stood up after a trial of some rapist and said that I'm willing to murder my son so that this rapist goes free?
Salvation didn't work
Salvation was supposed to fix the world. The Easter Vigil is filled with pompous words about “defeating death”, “destroying sin”, “defying satan”, etc. etc.
Has any of those promises really been delivered? Why do we still sin, if the “Lamb of God, took away the sins of the world”? If time is irrelevant and Jesus died for the future sins too, why are there still consequences for sinning? How is Satan still scary? How does any of it make sense?
Sooo... god created us flawed and wants to punish us for being flawed. Except really he doesn't, he'd rather save us from his own rage. So he has sent himself (aka. his son) to be killed (but not really) so that his suffering teaches us a lesson and removes all the sin, suffering and death, except all of them are still there.