That is simply an assumption -- reading into the text what is not there. You will not find the word *saint* in this chapter, but you will find the word *earth*. The *harvest of the earth* is not *the harvest of the saints*. The *vine of the earth* is not Christ the Vine. Please note how many time *earth* appears in this small passage. This is the harvest of the *tares* since the *wheat* is already safely in the barn.
Rev 14:14 And I looked, and behold a white cloud, and upon the cloud one sat like unto the Son of man, having on his head a golden crown, and in his hand a sharp sickle.
Rev 14:15
And another angel came out of the temple, crying with a loud voice to him that sat on the cloud, Thrust in thy sickle, and reap: for the time is come for thee to reap; for the
harvest of the earth is ripe.
Rev 14:16 And he that sat on the cloud thrust in his sickle on the earth; and the earth was reaped.
Rev 14:17
And another angel came out of the temple which is in heaven, he also having a sharp sickle.
Rev 14:18 And another angel came out from the altar, which
had power over fire; and cried with a loud cry to him that had the sharp sickle, saying,
Thrust in thy sharp sickle, and gather the clusters of the vine of the earth; for her grapes are fully ripe.
Rev 14:19 And the angel thrust in his sickle into the earth, and
gathered the vine of the earth, and cast it into the great winepress of the wrath of God.
Looks like two different angels to me as one reaps the harvest which are we as God is Lord of the harvest. Matthew 9:37,38; Luke 10:2; John 4:35-38; 1Corinthians 3:6-9 are just a few verses that speak about the harvest being that of Gods children who have ears to hear and are reaped and gathered to eternal life as God is Lord of His harvest. The tares refused to hear and are also reaped and gathered to the lake of fire.