Nice. Next question – this is one I never get.
Why did mankind need saving?
It’s totally acceptable to say that this is partially a mystery.
The basic answer is: We are created good, in general. But each one of us has a bad streak inside us that rebels against, and consequently alienates us from, God - the source of all good, love, truth.
The Creator is perfect, yet we are imperfect. Saving means making us perfect.
Perfection cannot abide imperfection (there is no sin in Heaven) and in order to wipe out that sinful streak that we all have... that is where God comes in and helps us.
If the will of God is perfect, and imperfection cannot exist in Heaven, then for us to get to Heaven, our wills must be made in line with that of the source of all that is good and perfect. That is "saving."
This bad streak is called original sin. No matter what you call it, or how you think it came to be like that, no one can deny that people have problems. Everyone idealizes about a world where people love and respect each other, one where people are not selfish, and one with peace always. But all the systems that try and accomplish this inevitably fail. Because a part of human nature is selfish, it gets a rush out of doing illegal or forbidden, that type of stuff. That doesn't fly in Heaven, but Heaven is where God is. God, being the Creator, loves all of His creation, and desires to have a mutual relationship of love with all creation. And to do that He needs to “save” us.
I hope that is a decent explanation.