From the vision of Enoch we learn that there are millions of earths like this one. In that context, Enoch was taught that there are those on this earth that are committing the most wickedness of all the workmanship of the Lord's hands (Moses 7: 29-35). The Lord has certainly counterbalanced that wickedness by sending some of the most righteous here, including the Savior, the heads of each dispensations, and many others of his righteous spirit children. Nevertheless, their are great challenges for those committed to turning this earth into a Celestial Kingdom. Apparently more challenges than any other earth of the Lord's creations.
President Brigham Young had a view on this subject, (click image to enlarge)