[How could a loving God let this happen?]
I understand the frustration. Believe me, oh too well (though in other ways). So, it’s our fault.
However, WE handed over the planet to Satan at the Garden of Eden. And each of us has contributed to his (temporary) reign. That is called “sin” and we’re all guilty of it.
Jesus Christ will dethrone him, permanently. At His Second Coming (though Satan gets one last round after the 1,000-year reign).
That is why Jesus called Satan, “the prince of this world”.
John 14:30 King James Version (KJV)
30 Hereafter I will not talk much with you: for the prince of this world cometh, and hath nothing in me.
John 16:11 King James Version (KJV)
11 Of judgment, because the prince of this world is judged.
The Apostle Paul called Satan “the god of this world”:
2 Corinthians 4:3-4 King James Version (KJV)
3 But if our gospel be hid, it is hid to them that are lost:
4 In whom the god of this world hath blinded the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them.
Whoops - put that in the wrong place - corrected:
However, WE handed over the planet to Satan at the Garden of Eden. And each of us has contributed to his (temporary) reign. That is called sin and were all guilty of it. So, its OUR fault (that the planet is the way it is).
"...we handed-over the planet..."