For God so loved the world that he gave his only Son, so that everyone who believes in him might not perish but might have eternal life.
The more I think about this verse, the more amazing it is.
A sacrifice of one's own life for someone else is a truly great thing. Someone (I completely forget who) once said that any of us might sacrifice our lives for an innocent person, but how many of us would die tosave a guilty person? That's what Jesus did for us. He gave His life so that we might not suffer eternal punishment, despite the fact we are all guilty of many sins and therefore not deserving of salvation. But so great was His love for us that He suffered and died anyway so that we might be able to receive salvation.
But let's look at God the Father's sacrifice, which might have been even greater. My senior year of high school a classmate died in a car accident. We had a Mass for him during school hours that shortened classes that day. Before heading down to it, our history teacher told us to hurry back up after it was over so we could get to work since we had a lot of catching up to do. After Mass ended, we went straight back to the classroom ready to continue with the lesson. Once she arrived, she was crying so much that she couldn't teach. All she said was that we'd understand when we were parents because we'd rather suffer anything that have that happen to our children.
I often think of that when thinking about the Crucifixion. Any parent (I imagine, I have no children myself, but based on the above story and other comments like it) would suffer greatly rather than see any harm come to their children. So what's God is telling us is that He not only loves us enough to die for us Himself, but He loves us so much that He would allow His only Son to be tortured and die in order to save us
. Based of my history teacher's comments that may have been an even greater sacrifice.