D&C 4

In a revelation to the father of the Prophet Joseph Smith, the Lord provides instruction to any and all saints saying -

"...O ye that embark in the service of God, see that ye serve him with all your heart, might, mind and strength, that ye may stand blameless before God at the last day."  (Doctrine and Covenants  Section 4:2)

And then reviews the eternal laws related to such diligent service -

"...behold the field is white already to harvest; and lo, he that thrusteth in his sickle with his might, the same layeth up in store that he perisheth not, but bringeth salvation to his soul..."  (Doctrine and Covenants  Section 4:4)

Suggesting that if one desires salvation and exaltation, it is conditional up serving God with "all your heart, might, mind and strength", or in other words, doing the best you can.

The field is white would suggest to me that there are many of the elect or those that will accept the gospel, repent in such a manner that the "fruit" will be made white through the atonement of Jesus Christ.  We are reminded of this harvest -

"That the work of the gathering together of my saints may continue, that I may build them up unto my name upon holy places; for the time of harvest is come, and my word must needs be fulfilled.
65 Therefore, I must gather together my people, according to the parable of the wheat and the tares, that the wheat may be secured in the garners to possess eternal life, and be crowned with celestial glory..."  (Doctrine and Covenants  Section 101:64 - 65)

In my mind, the garners then would be "upon holy places", one of which would be His Holy Temple.  This is our purpose in harvesting the ripe field for -

"...ye are called to bring to pass the gathering of mine elect; for mine elect hear my voice and harden not their hearts..."  (Doctrine and Covenants  Section 29:7)