God created out of an overflow of love. It is by his nature that we were created. There is no other possible universe that could exist except this one. He created with the express purpose of showing how glorious he is; in that, the nature of his being is to suffer willingly on the behalf of others. It is in the very nature of goodness to do good in the face of adversity. If humans had no adversity, no suffering, no pain, there could be no way we manifest the divine in the world. The glorious gospel is that we can be like him just as he is, and he has shown us that it is in the nature of God to love, and the nature of love is to suffer voluntarily on the behalf of others. That is the message of the cross, divine love, and the fulcrum of all of existence.
He didn't set us up, he gave us the best possible universe in which beings which are not him can survive and thrive, it takes "faith the size of a mustard seed." And we fail to choose that more often than not.
And the atonement is more than some flippant party trick God plays on himself. It is a legal declaration of righteousness on behalf of the sinner, that in no way could the sinner ever manifest for himself. It is glorious precisely because it is God who is the only one who could do it.
This is an old question answered about 1500 years ago by St.Augustine. look up Felix Culpa.
Study more Christian theology, you'll find your answers.
