They will no longer experience the privations and discomforts of their earthly existence (cf. Isaiah 49:10, LXX John 4:14; John 6:35; John 7:37). The Lamb, now seen standing before the middle of the throne, will provide for them as a good shepherd takes care of his sheep (cf. Psalm 23:1-4; Isaiah 40:11; Ezekiel 34:23; John 10:11; John 10:14; Hebrews 13:20; 1 Peter 2:25; 1 Peter 5:2-4). He will refresh them as well as protect them (cf. Exodus 15:13; Deuteronomy 1:33; Psalm 5:11-12; Psalm 85:11; John 16:13). The Lamb will lead these sheep to God who is the fountain of life ( Revelation 21:6; Revelation 22:1; Revelation 22:17; cf. Psalm 35:10; John 4:12; John 4:14; John 7:38-39). As a loving parent, he will wipe away the tears they shed because of their sufferings (cf. Revelation 21:4). [source][source][source]
"The ultimate fulfillment of these seven promises ( Revelation 7:15-17) will come in the eternal state described more fully in Revelation 21-22 , but John"s "snapshot" of the innumerable multitude catches them in heaven at a point just before the beginning of the last half of the seven years of Daniel"s seventieth week." [1][source]
"While each of the seven rewards contains some aspect of literal fulfillment, each one also figuratively pictures God"s pledge to be present with Tribulation saints to protect, shepherd, and comfort them in the eternal state ( Revelation 7:15-17). These rewards are also promised for today"s believers in order to encourage them to be faithful ( Revelation 21:1-5)." [2][source]
The location of this revelation in the context of John"s visions is significant. It strongly argues for these two groups, the144 ,000 living Jewish believers and the multitude of dead believers, existing during the Tribulation after Christians have gone to heaven at the Rapture. God will save multitudes of people during this time. It will be harder for all people to believe the gospel after the Rapture than it is now. However it may not be impossible for people who have rejected it before the Rapture to believe it from then on (cf. 2 Thessalonians 2:11-12). [source][source][source]
The Literary Structure of Chapters6-18The SealsFIRST SIX(ch. 6)Supplementary Revelation(ch. 7)SEVENTH(chs8-16)The TrumpetsFIRST SIX(chs8-9)Supplementary Revelation( Revelation 10:1 to Revelation 11:14)SEVENTH( Revelation 11:15 to Revelation 16:21)Supplementary Revelation(chs12-15)The BowlsFIRST SIX( Revelation 16:1-16)SEVENTH( Revelation 16:17-21)Supplementary Revelation(chs17-18)[source]