1 Peter 1:14-16 - As obedient children, do not conform to the evil desires you had when you lived in ignorance. But just as he who called you is holy, so be holy in all you do; for it is written: “Be holy, because I am holy.”
God is perfectly just. This is the excuse many fundamentalist Christians use to justify the atrocious behavior of their god. This is why God needed animal sacrifices in the Old Testament, and it's why Jesus was killed in the New Testament. It's why God created a Hell, so that people would pay for their sins. Basically, God demands a sin be punished. A sin is like a debt, and it doesn't matter who pays the debt so long as it is paid.
But something has been bothering me lately. If Christians are supposed to be holy, and to live according to God's standards, and to imitate his perfect nature to the best of their ability...why don't Christians use the same system of justice? If someone offends a Christian and the Christian just forgives their offender freely, that's not justice. The Christian should withhold their forgiveness until the sin has been paid for. They should grab their pet Mittens and cut its head off, sprinkling the blood of their cat onto their offender. Only then will their sin be washed clean.
Ah. But that would only be a temporary solution to the problem. Because we're all sinful, that person would inevitably need another sacrifice sometime down the line. So the solution is simple. Either hoard cats or make a permanent sacrifice. One that will cover both past transgressions and those that could be made in the future. By modeling God's system of justice, the perfect sacrifice would have to be an innocent human who takes the place of the transgressor. And because God sacrificed himself through his human incarnation named Jesus, the obvious conclusion is that every Christian should kill him or herself in order to forgive the people who sin against them. Only then will true justice be done on earth.
Now just imagine if this same principle were applied to the justice system of a country. The United States can hardly claim to be "one nation under God" when they apply fines, jail sentences, and rehabilitations to those who break the law. When a murderer goes to trial, let the families of the victims be given the lethal injections. When a serial child rapist is put on trial, put the children who were raped behind bars. This is how true justice works. Let's make America great by making it the first nation in history to live by God's holy standards.