“Note the contrast between these chapters and the proceeding ones. Here we see the holy angels and the Lamb surrounded by his joyous followers. In Revelation 12 and 13 we saw the three unholy ones, the dragon and the two beasts.
Here we see the mark which identifies those who belong to the Lamb. There we saw the mark of the beast. Here is beauty, joy, glory, triumph, singing, music, majesty. In the preceding chapters were fear, deceit, hatred, blasphemy, men worshiping the dragon rather than the Lamb, persecution of the saints, and satanic signs and activity.
In Revelation 12 and 13 we were looking from the earthly perspective. In Revelation 14 and 15 we are looking from the heavenly perspective. In the Old Testament, Zion referred to the city of God, the earthly Jerusalem. Here it refers to the new Jerusalem, heaven itself, and points forward to the final victory which is coming to the saints when all of history will have found its consummation in Christ.
The redeemed have the name of Jesus and the Father on their foreheads. He is their love, their joy, their thought, their all. And he loves them with an everlasting love. He has been with them through every trial and now they are at home with him, safe and victorious in the Father’s house. Every one of them is there. The 144,000 refers to the sum total of all the redeemed. We do not know how many that is, but God knows. He knows the name of every one of his redeemed; not one of his own will be missing."
from Courage for Today, Hope for Tomorrow by Esther Onstad