Because in the times of Adam and Eve, we were made in the image of God, to be with God. Thats why we're in this mess now. Because we were designed, in the image of God, to commune with God. But now when the world creates so many other 'gods', many cannot focus on the true God, which we were created to commune with.

We were designed to be with God. I now find, our sense of lacking in this world, is because we are not doing what we were designed to do.
Like a fisherman without his bait, he will keep fishing, but he lacks, and the rod would never satisfy.