The Church of Philadelphia are the 144,000 that are reaped in Rev. 14:15

Some elderly-weak who accept the Truth will be laid to rest before the Hour of Temptation.

Revelation 14:12
12 Here is the patience of the saints: here [are] they that keep the commandments of Elohim, and the faith of Y'hoshua.

Revelation 14:13
13 ¶ And I heard a voice from heaven saying unto me, Write, Blessed [are] the dead which die in Y'hovah from henceforth: Yea, saith the Spirit, that they may rest from their labours; and their works do follow them.

Revelation 14:14
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.

Revelation 14:15
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.

Revelation 14:16
16 And he that sat on the cloud thrust in his sickle on the earth; and the earth was reaped.

Revelation 14:17
17 And another angel came out of the temple which is in heaven, he also having a sharp sickle.

Revelation 14:18
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.

Revelation 14:19
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 Elohim.

Revelation 14:20
20 And the winepress was trodden without the city, and blood came out of the winepress, even unto the horse bridles, by the space of a thousand [and] six hundred furlongs.

Amos 8:3 And the songs of the temple shall be howlings in that day, saith Adonai Y'hovah: [there shall be] many dead bodies in every place; they shall cast [them] forth with silence.

The Church of Laodicea are the SDA's left upon earth called the synogogue of satan-(see 'A Word to the Little Flock'), which are slaughtered in Eze. 9 and Amos 8:3

Matthew 24:40
40 Then shall two be in the field; the one shall be taken, and the other left.

Matthew 24:41
41 Two [women shall be] grinding at the mill; the one shall be taken, and the other left.

Luke 17:36
36 Two [men] shall be in the field; the one shall be taken, and the other left.

Luke 17:37
37 And they answered and said unto him, Where, Master? And he said unto them, Wheresoever the body [is], thither will the eagles be gathered together.

Amos 8:3 And the songs of the temple shall be howlings in that day, saith Adonai Y'hovah: [there shall be] many dead bodies in every place; they shall cast [them] forth with silence.

Two thirds are slaughtered but 1/3 left to say "blessed is he that cometh in The Name of Y'hovah".

Zechariah 13:7
7 ¶ Awake, O sword, against my shepherd, and against the man [that is] my fellow, saith Y'hovah of hosts: smite the shepherd, and the sheep shall be scattered: and I will turn mine hand upon the little ones.

Zechariah 13:8
8 And it shall come to pass, [that] in all the land, saith Y'hovah, two parts therein shall be cut off [and] die; but the third shall be left therein.

Zechariah 13:9
9 And I will bring the third part through the fire, and will refine them as silver is refined, and will try them as gold is tried: they shall call on my name, and I will hear them: I will say, It [is] my people: and they shall say, Y'hovah [is] my Elohim.

The Church of Philadelphia are the 144,000 sealed, mostly from the SDA Churches, and those coming into the Truth. They do not suffer the punishment of Revelation 14:17, which is Laodicea, many are slaugtered by Ezekiel 9's "men with the slaughtering weapons".
Philadelphia is kept from "the hour of temptation" see Revelation 3:10

Revelation 3:6
6 He that hath an ear, let him hear what the Spirit saith unto the churches.

Revelation 3:7
7 ¶ And to the angel of the church in Philadelphia write; These things saith he that is holy, he that is true, he that hath the key of David, he that openeth, and no man shutteth; and shutteth, and no man openeth;

Revelation 3:8
8 I know thy works: behold, I have set before thee an open door, and no man can shut it: for thou hast a little strength, and hast kept my word, and hast not denied my name.

Revelation 3:9
9 Behold, I will make them of the synagogue of Satan, which say they are Jews, and are not, but do lie; behold, I will make them to come and worship before thy feet, and to know that I have loved thee.

Revelation 3:10
10 Because thou hast kept the word of my patience, I also will keep thee from the hour of temptation, which shall come upon all the world, to try them that dwell upon the earth.

Revelation 3:11
11 Behold, I come quickly: hold that fast which thou hast, that no man take thy crown.

Revelation 3:12
12 Him that overcometh will I make a pillar in the temple of my Elohim, and he shall go no more out: and I will write upon him the name of my Elohim, and the name of the city of my Elohim, [which is] new Jerusalem, which cometh down out of heaven from my Elohim: and [I will write upon him] my new name

Revelation 14

Revelation 14:1
1 ¶ And I looked, and, lo, a Lamb stood on the mount Sion, and with him an hundred forty [and] four thousand, having his Father's name written in their foreheads.

Revelation 14:2
2 And I heard a voice from heaven, as the voice of many waters, and as the voice of a great thunder: and I heard the voice of harpers harping with their harps:

Revelation 14:3
3 And they sung as it were a new song before the throne, and before the four beasts, and the elders: and no man could learn that song but the hundred [and] forty [and] four thousand, which were redeemed from the earth.

Revelation 14:4
4 These are they which were not defiled with women; for they are virgins. These are they which follow the Lamb whithersoever he goeth. These were redeemed from among men, [being] the firstfruits unto Elohim and to the Lamb.

Revelation 14:5
5 And in their mouth was found no guile: for they are without fault before the throne of Elohim.

Revelation 14:6
6 ¶ And I saw another angel fly in the midst of heaven, having the everlasting gospel to preach unto them that dwell on the earth, and to every nation, and kindred, and tongue, and people,

Revelation 14:7
7 Saying with a loud voice, Fear Elohim, and give glory to him; for the hour of his judgment is come: and worship him that made heaven, and earth, and the sea, and the fountains of waters.

Revelation 14:8
8 And there followed another angel, saying, Babylon is fallen, is fallen, that great city, because she made all nations drink of the wine of the wrath of her fornication.

Revelation 14:9
9 And the third angel followed them, saying with a loud voice, If any man worship the beast and his image, and receive [his] mark in his forehead, or in his hand,

Revelation 14:10
10 The same shall drink of the wine of the wrath of Elohim, which is poured out without mixture into the cup of his indignation; and he shall be tormented with fire and brimstone in the presence of the holy angels, and in the presence of the Lamb:

Revelation 14:11
11 And the smoke of their torment ascendeth up for ever and ever: and they have no rest day nor night, who worship the beast and his image, and whosoever receiveth the mark of his name.

Revelation 14:12
12 Here is the patience of the saints: here [are] they that keep the commandments of Elohim, and the faith of Y'hoshua.

Revelation 14:13
13 ¶ And I heard a voice from heaven saying unto me, Write, Blessed [are] the dead which die in Y'hovah from henceforth: Yea, saith the Spirit, that they may rest from their labours; and their works do follow them.

Revelation 14:14
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.

Revelation 14:15
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.

Revelation 14:16
16 And he that sat on the cloud thrust in his sickle on the earth; and the earth was reaped.

Revelation 14:17
17 And another angel came out of the temple which is in heaven, he also having a sharp sickle.

Revelation 14:18
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.

Revelation 14:19
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 Elohim.

Revelation 14:20
20 And the winepress was trodden without the city, and blood came out of the winepress, even unto the horse bridles, by the space of a thousand [and] six hundred furlongs.