The free will part is good. But you could look at little closer at the saves us from sin part. It's a lot more that platitude, What if justice and mercy both have to be kept in balance. What if Jesus volunteered to pay that price because he was going to be also be able to pay the price our our sins. So that Justice was satisfied. God can forgive, but Justice to come to play as well. SO it's kids of a Twofer. Gethemane first, where the price of the sins was paid then Calvary where the actual Physical death came. And free will still comes into it, Jesus Still vounteered, and we still have the free will to say no not interested. In the first part any way. The Second part was a gift. As to Why Jesus Volunteered? He loved, sorry Loves us.

My head is a little wibbily this morning, I tried a new sleeping combo last night, And it worked. I hope the above a reasonably clear. Yes I'm a Christian, I hope I can be awake enough to participate in this one.