D&C 133

As the Lord commands -

"HEARKEN, O ye people of my church, saith the Lord your God, and hear the word of the Lord concerning you—" (Doctrine and Covenants | Section 133:1)

...my thoughts were are two principles He commands us to hearken to -

"...prepare ye, prepare ye, O my people; sanctify yourselves; gather ye together, O ye people of my church, upon the land of Zion, all you that have not been commanded to tarry.
5 Go ye out from Babylon. Be ye clean that bear the vessels of the Lord." (Doctrine and Covenants | Section 133:4 - 5)

First we must worthily commit to sanctify or consecrate ourselves to the Lord and be clean in our thoughts and doings. Second as we go out from
"spiritual" Babylon -

"...let him not look back lest sudden destruction shall come upon him." (Doctrine and Covenants | Section 133:15)

In my mind, looking back is somewhat longing for the days of Babylon. The consequence could be catastropic in the one may fall or experience sudden destruction. We -

"...must press forward with a steadfastness in Christ..." (Book of Mormon | 2 Nephi 31:20)

But in doing so -

"...let not your flight be in haste, but let all things be prepared before you..." (Doctrine and Covenants | Section 133:15)