Jesus crucifixion didn't remove original sin, it gave us a way to be free from the consequences of it.
Answer 3
Answer 2
Original sin is why mankind is in a fallen state. However, that's not our fault. We're born into this system but we're not going to be held accountable for it. We have our own sin which is why we're under the judgment of God.
Answer 1
As we still have to ask God/Jesus for forgiveness, as we always did, why was a crucifixion necessary?
Straightening out the Spaghetti
We're going to straighten out the spaghetti but it can get bogged down in technicalities, which is why having a simple answer is preferable.
A Simple Answer
Salvation 1. Call upon the name of Jesus Christ, believe in your heart that God raised him from the dead, 2. confess your sin.
Propitiation
Propitiation is the price paid for our redemption. This was Jesus himself. He lived a sinless life and his sacrifice was sufficient to pay for the sins of the whole world.
Redemption
We've resolved a theory of gravitation with the plan of redemption. It's part of a unified theory of everything. Redemption is a gift of God's grace, it's freely available to all who call upon the name of Jesus Christ.
Justification
How can I become righteous? The only way is if the righteousness of God could be imputed to me, so that when God looks at me he won't see my sin, he'll see his righteousness.
My Sin
Salvation doesn't have an App 1. Call upon the name of Jesus Christ, believe in your heart that God raised him from the dead, 2. confess your sin.
The Cursed Earth
Original sin brought the curse of decay and physical death to our bodies. Yet there was another consequence beyond our physical bodies, God also cursed the Earth which began to decay. Nuclear decay.