Because He created us (Mankind) with Free Will.
Because we chose to live apart from God.
Because we have chosen Evil. For now, He is letting us.
In The Beginning… At first, we (humanity) were with God, and what was GOOD was what was of God. Good WAS God, and God WAS Good. Simple.
Then Satan convinced Humanity that we could… even should… define Good on our own… how dare God claim the sole right to define Good vs. Evil? Adam and Eve ate of the Tree of the Knowledge of Good and Evil and were not given a gift — they were rather SEPARATED from reliance on God for the definition of Good. We are still separate.
We have a dim view into God’s presence through His written word, through preserved stories of His interactions with our ancestors, and in the life lessons left to us by His Son, who visited us just 33 short years. We have help in understanding, in a limited way, through the Holy Spirit which is a gift that leads… but it is not the same as living in a world that is ruled by our Creator. It’s not the same as Adam and Eve experienced in being able to converse with Him in any waking moment. We lost that when Adam and Eve made the decision to define Good and Evil without RELYING on God to do that for us.
Now, we wait for Christ’s return… and it’s a long wait for us; but a short time for God. He is watching us learn how futile it is for us to live in peace and prosperity while being separate from Him.
We are living in Australia — the place that criminals were sent (Satan and a third of the angels who rebelled against God and were cast down), and are still in charge here. At Jesus Christ’s return (Second Coming), those criminals will no longer rule, and our environment will not belong to disrupters and those who thrive on Evil — but we will still have Free Will, as that is how God created us.
The difference will be that Good and God will no longer be separate, either. He will define what He wants for us, and only in communing with Him will we be capable of Peace.
We have had thousands of years to attempt to achieve it on our own… defining Good as anything else but ‘with God and of God‘ is futile. Bad things happen — wars, assaults, lying, pretense, famine, disease, hate, abuse, theft, loneliness and death — because since the time of Adam and Eve, we have been choosing (as a race) to define Good out of our own feeble minds and frail hearts.
This is not God’s doing — it is not His will. It is Satan’s world, and Satan’s will that we live apart from God, and suffer endlessly — as he knows we are to inherit a place with God that he forfeited long ago.