We have hope because we have faith! Faith in the one true Son of God, Jesus Christ, who loves us so much He freely gave His life for us!
How do I know this? Lets look at what the Bible says about it. I am using The Message translation of the Bible for the ease of understanding - I like this version because it puts it in today's language.
"This is how much God loved the world: He gave his Son, his one and only Son. And this is why: so that no one need be destroyed; by believing in him, anyone can have a whole and lasting life. God didn't go to all the trouble of sending his Son merely to point an accusing finger, telling the world how bad it was. He came to help, to put the world right again. Anyone who trusts in him is acquitted; anyone who refuses to trust him has long since been under the death sentence without knowing it. And why? Because of that person's failure to believe in the one-of-a-kind Son of God when introduced to him." ~ John 3:16-18 (The Message)
Want to know more about how to put your faith in Jesus Christ?
http://www.sbc.net/knowjesus/theplan.asp