D&C 133

In preparation to the second coming of the Savior, the Lord describes two gatherings that was to take place wherein the Lord said first -

"Let them, therefore, who are among the Gentiles flee unto Zion."  (Doctrine and Covenants | Section 133:12)

And then -

"...let them who be of Judah flee unto Jerusalem, unto the mountains of the Lord's house."  (Doctrine and Covenants | Section 133:13)

I see the gathering of the "Gentiles" to be in relationship to the doctrine and gospel of Jesus Christ more than to a location, where the Jews are to gathered in relationship to a location, being Jerusalem.  This seem apparent as the Lord instruct -

"...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."  (Doctrine and Covenants | Section 133:4)

And as the people accept His gospel -

"...Go ye forth unto the land of Zion, that the borders of my people may be enlarged, and that her stakes may be strengthened, and that Zion may go forth unto the regions round about."  (Doctrine and Covenants | Section 133:9)

These stakes of Zion would scattered throughout the world.  In order to "sanctify" ourselves, as we gather, we must -

"Go ye out from Babylon. Be ye clean that bear the vessels of the Lord."  (Doctrine and Covenants | Section 133:5)

Even -

"Go ye out from among the nations, even from Babylon, from the midst of wickedness, which is spiritual Babylon.
15 But verily, thus saith the Lord, let not your flight be in haste, but let all things be prepared before you; and he that goeth, let him not look back lest sudden destruction shall come upon him."  (Doctrine and Covenants | Section 133:14 - 15)

Much like Lot's wife, we must not look back or in other words, long for Babylon.

Recently, we had a stake  handcart trek with the theme, "Come, Come Ye Saints" suggesting an invitation to come to Christ.  In order to come, we must flee.  We must flee Babylon and not look back.