Love does not torture needlessly. Love does not require the pain of eternity. There is literally NOTHING just about such an arrangement. For one, it makes the statement that somehow, we finite beings have managed to change the unchanging God, to somehow infinitely offend God. And if that were the whole of the story of sin, all God would have needed to do is forgive us. Notice that God has never said that hell is the result of His wrath. This is the problem with a purely penal view of sin. It acts as if, somehow, God NEEDS a sacrifice to forgive sin. But look at the lame man lowered through the roof of the house, and various other people that Christ forgave without any need for a sacrifice which had not yet been performed. God is not limited to forgiving us through a sacrifice. That is, He doesn't if He is somehow all powerful.
However, there are two other reasons that the word "just" is misunderstood in the Scripture. For one, forgiveness of sins is not just in the least, even with a substitutional sacrifice. One is judged by his own deeds, and not the deeds of others, making it impossible for the sins of one to be passed on to the Christ if they were purely a violation of legal codes. It is not just for God to exact punishment of His Son on our behalf, not as we count justice. Justice, in its pure form in a legal sense, is ALWAYS going to exact the penalty of the perpetrator of the crime.
For another, it is not just for God to judge the life of any man based on the sins of any other, be he brother, sister, father, or primary ancestor. Remember how Paul says we are judged by our own deeds in Romans 2. Justice, in its pure form, does not pass the crimes of one to another. It is blind and unwavering, but it is, in its own way, completely fair. However, in the western world, justice goes out the window when it comes to the sins of Adam and Eve. In fact, the thought that sin was passed by way of procreation to the young, rather than by secondary infection, is the very reason that such doctrines as the Immaculate Conception were thought up. If Christ was incapable of sin in His human form, and sin is an integral part of human nature, then Christ is not of the same essence with us. But if sin is seen as a shortcoming, an imperfection in the image of God placed in all of us, and not a necessary part of the human nature, then Christ is of the same essence with us.
This is why I pretty much gave up the ideas of justice, because in reality, God is not "all just". Not in the way that humans consider just. If He were, then I couldn't believe in forgiveness or in the condemnation of those who did not willingly partake in an action they are being condemned for. It makes no logical sense for forgiveness to exist within justice, or even for the concept of pure substitutionary atonement.
In all reality, the "punishment" of hell is something the sinner creates for himself in his rejection of God. Much as the difference between being burned by a fire because one doesn't respect the power of the flames, and toasting marshmallows around it while being warmed against the cold of night is the respect one has for the flame, so also is our relationship with the All Consuming Firethat is our God. In this, we are the creators of our own hell, and of our own punishment. God does not cause pain without purpose, and that is all that hell is. Hell is a pain brought about by our own decisions to go against God. It is us jumping over the flame, daring for it to catch us as we drunkenly fool around. The pain and anguish is our own faults, if we choose to reject God. It is not the fault of God. He does not create it, for what is the purpose thereof? There is none.