Revelation 7: 9 After this I beheld, and, lo, a great multitude, which no man could number, of all nations, and kindreds, and people, and tongues, stood before the throne, and before the Lamb, clothed with white robes, and palms in their hands; 10 And cried with a loud voice, saying, Salvation to our God which sits upon the throne, and unto the Lamb.
Revelation 14:1 And I looked, and, lo, a Lamb stood on the mount Sion, and with him a hundred forty and four thousand, having his Father's name written in their foreheads. 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. 4 These are they which were not defiled with women; for they are virgins.
When John says that they were redeemed from the earth he is referring to the 144,000 who, translated to heaven without seeing death, now stand upon the sea of glass. On this point there is great need of clarity, for there are many other saints who will be resurrected, just before Jesus comes, and who would be alive on the earth to witness His coming in person.
But the main difference is that they will have passed through the portals of the tomb previously. Daniel alludes to this fact when he speaks of the many that sleep in the dust of the earth. …Daniel 12: 2 And many of them that sleep in the dust of the earth shall awake, some to everlasting life, and some to shame and everlasting contempt.
Revelation 14:These are they which follow the Lamb whithersoever He goes. These were redeemed from among men, being the first fruits unto God and to the Lamb.
May The Lord add His blessing to the study of His word. God bless!