Why is the Lord’s course one eternal round?

I realize that good is able to not be turned to the right or to the left because of His infinite time scale—He’s not limited to accomplishing His purposes in 5 minutes, 5 years, or 5 decades—but also because no matter what happens He does not lose focus on His ultimate objective. The posterity of Nephi can fall away, the gentiles can be confused by the works of the great and abominable church, and the Jews can lose sight of the real purpose of their covenant heritage but through all that the Lord still puts His every effort into bringing to pass the immortality and eternal life of man.