Sounds ludicrous at first glance doesn't it. Until you stop and think what is sin and what are the consequences of sin? Well we can look around today in this age of freedom and see the results of sin. Murders, hatred, abortions, unwanted children left to fend for themselves, the breakup of families, adultery, hurt and pain everywhere you look.
How can God being a God of Justice not judge sin. He told us plainly before Adam ever sinned that the penalty would be death.
But God loves us? Well, he doesn't love all the things we do, but He loved us enough to pay the penalty for our sins. He died so we don't have to. There's just one little catch. You have to plea, you have to agree to the substitution. If you don't you are in continued rebellion against God and that's the one sin that will still send you to hell. But if you do, you are home scott free.
Not really a bad deal when you think about it. God really does love us. Why more people don't take Him up on His offer is really beyond me. I guess it sounds too good to be true.