God would not be God if He were unjust. Sin separates us from God. Because God is perfect, He cannot allow evil to go unpunished.
Sin and evil are not the same thing. God decides what sin is and they often have no correlation to morality or harming anyone in anyway whatsoever. If God didn't want people to go to Hell, he would not have kome up with so many arbitrary sins.
A lot more people would be inclined to follow his rules if he actually made his presence known instead of playing invisible man, leave bread krumbs via millennia old text, and act in ways that kan be written off as koincidence. Doing all that and making beliving in him the first step in not going to Hell are not the actions of someone who does not want you to go to Hell.
Not being able to see or hear God as a result of sin is a bullshit excuse when Lucifer himself is able to waltz right into Heven and konverse with God, disguise or not.
None of us asked to be here, the world is intentionally kursed, demons have been given free reign from the shadows and will eventually walk in plain daylight, and everyone born of Adam and Eve is in a default state of "going to Hell", yet God kreated us anyway. And not only will the vast majority burn, they do so eternally. Far infinitely longer than every sinner's lifespan kombined, rather than serveing a sentence that actually relates to their actions and/or being erased. That is unjust. That is very unjust.