The Lord's prayer invites God's Kingdom to come to Earth, as it is in Heaven (Matt 6:9-13). An essential part of any kingdom is healthy, righteous, justice. This should mean that as the Kingdom continues its advance, human justice should transform into Godly justice, no? There have been plenty of examples of people groups coming to Christ, then being inspired to right wrongs in the civil arena. This happened with the abolition of slavery, the implementation of capital punishment, even the recognition of essential human rights (as outlined in our Bill of Rights). Despite the slow march towards making Earth a God fearing globe, there seems to be one irreconcilable difference between how humans ought to think about justice, and how God does think about justice.
(You may be thinking; hey Matt, your a few months late to the Kavanaugh party, why don't you find another tree to bark up?...and you may be right, but I consider justice timeless, and I like this tree just fine.)
In light of God's holiness and man's fallen lineage, humans are guilty until proven innocent (Rom 3:9-12). Contrast this with American justice in which you are innocent until proven guilty. The burden of proof is on the accuser in our justice system. Wouldn't it be more Godly of us to assume an accused person committed a crime, however? We certainly know they are a sinner, and sinners are worthy of death, so if we are to bring the kingdom to earth why shouldn't we prosecute every last soul? The logical outworking of this prayer seems to lead to human extinction...and all the ecologists cheered. If only there was a text that could provide some governors on our zeal...Perhaps wherever we got that first reading, about something being on earth as it is on heaven? The same Lord's prayer in Matt 6:12 also commands us to forgive our debtors, because our debts are also forgiven (it seems safe to assume this is referring to the wages of sin which are death). So now nobody dies. Do the criminals just remain unpunished then?
It seems we are back to square one. How are we to judge then? Deut 19:15 instructs that no one can be convicted unless on account of two or three witness, and false witnesses will be punished for the crime they falsely testified about. This seems like some concrete ground to set our backwards justice on, and in case you have been listening to too much Andy Stanley, here's a New Testament reference; "Every matter must be established by the testimony of two or three witnesses." (2 Cor 13:1). Paul clearly had not unhitched the Old Testament yet. The New Covenant certainly seems to maintain this judicial practice as somewhat of an essential to execute proper justice. This still leaves us wondering what these commands for our justice system are telling us about prime reality.
If we conceptualize the supernatural conflict as judicial, i.e. the gates of hell will not prevail against the Church, then we find helpful symbolism. In Revelation 12:10 Satan is described as "the accuser". Satan's primary tactic is to accuse the saints that they are still guilty, that they aren't forgiven. With regards to the unregenerate he whispers that they don't need salvation, or that God couldn't save them...or really any number of lies. He desires their condemnation, he wants them to doubt and despise the Judge. Since we all are sinners, we can feel the touch of truth in all of the accusations. This is why we need a defense attorney. Jesus is the mediator, he intercedes for his children before his Father, the Judge. We are clothed with the innocence of Christ and Satan with his lies cannot prove us guilty, because he has no witnesses besides himself...and he is far from reliable. But when an unbeliever enters God's presence they must face an all knowing, triune witness, the defendant does not have a defense attorney and are left naked in their guilt.
The design of earthly justice that God gave us is not just a pragmatic solution to sinners trying to convict other sinners. It is fundamentally a way to play out the Cosmic courtroom drama. In the old covenant they were experiencing the shadows of the full mercy Christ would bring as a mediator. Now we live in a world where we truly can be counted innocent in the highest court. Commanding us to see our fellow man as innocent until proven guilty helps give us God crafted eyes. Our retinas are infused with his mercy as we are forced to see ourselves in the accused. All are guilty before God, but in His loving kindness he has graciously exonerated his chosen flock. Innocence must be assumed among men because we are deceitful accusers, children of Satan, that would undermine God's mercy if we were left to our own devices.