Joseph Smith
The righteous and the wicked [upon death] all go to the same world of spirits until the resurrection. (Teachings of the Prophet Joseph Smith, p.310)
Brigham Young
• When you lay down this tabernacle, where are you going? Into the spiritual world. Are you going into Abraham’s bosom. No, not any where nigh there, but into the spirit world. Where is the spirit world? It is right here. Do the good and evil spirits go together? Yes, they do. Do they both inhabit one kingdom? Yes, they do. Do they go to the sun? No. Do they go beyond the boundaries of this organized earth? No, they do not. They are brought forth upon this earth, for the express purpose of inhabiting it to all eternity. Where else are you going? No where else, only as you may be permitted. (Journal of Discourses, 3:369)