Yes...that need stopped on a Friday around 33 AD. It was confirmed on the following Sunday morning. No need for any additional sacrifices after that. It's called the resurrection.
To say that your past, present and future sins are forgiven does not have anything to do with time as you're attempting to place them. To be quite honest, I'm not really sure what kind of cosmological argument you're attempting to make. Reminds me of my philosophy class in college. Some weird stuff.
To say He's forgiven our past, present and future sins is a way of describing the complete forgiveness of our sins. Whether they're in the past or the ones we will sadly commit in the future. When we believe in Him, those sins are forgiven and covered. They're gone.
When we believe in Him, those sins are forgiven and covered. They’re gone.
That must be why protestants believe that birth control is ok.