“These are the ones that did not defile themselves with women; in fact, they are virgins. These are the ones that keep following the Lamb no matter where he goes. These were bought from among mankind as firstfruits to God and to the Lamb,

Revelation 14:4,

The fact that the 144,000 “are virgins” does not mean that members of this class are necessarily unmarried in the flesh. The apostle Paul wrote to Christians who had a heavenly calling that, whereas there are advantages to Christian singleness, marriage is preferable under certain circumstances. (1 Corinthians 7:1, 2, 36, 37) What characterizes this class is a spiritual virginity. They have avoided spiritual adultery with worldly politics and with false religion. (James 4:4; Revelation 17:5) As the betrothed bride of Christ, they have kept themselves pure, “without a blemish in among a crooked and twisted generation.”​—Philippians 2:15.

When Jesus was on earth, he invited righthearted ones to follow him. (Mark 8:34; 10:21; John 1:43) Those who responded imitated his way of life and obeyed his teachings. Thus, during their earthly course, they “keep following the Lamb no matter where he goes” as he guides them through Satan’s world.

14. (a) How is it that the 144,000 are “firstfruits to God and to the Lamb”? (b) In what sense are the great crowd also firstfruits?

¹⁴ The 144,000 are “bought from the earth,” “bought from among mankind.” They are adopted as sons of God, and after their resurrection, they will no longer be mere flesh-and-blood humans. As mentioned in verse 4, they become the “firstfruits to God and to the Lamb.” True, back in the first century, Jesus was “the firstfruits of those who have fallen asleep in death.” (1 Corinthians 15:20, 23) But the 144,000 are the “certain firstfruits” of imperfect mankind, purchased by means of Jesus’ sacrifice. (James 1:18) Nevertheless, the ingathering of fruitage from mankind does not end with them. The book of Revelation has already pointed to the harvesting of an unnumbered great crowd that cries with a loud voice: “Salvation we owe to our God, who is seated on the throne, and to the Lamb.” This great crowd will survive the great tribulation, and as they continue to be refreshed by “fountains of waters of life,” they will be raised to human perfection on earth. Sometime after the great tribulation, Hades will be emptied, and countless millions of other humans will be resurrected and have the opportunity to drink from those same waters of life. With this in mind, it would be correct to call the great crowd a firstfruits of the other sheep​—they are the first to ‘wash their robes and make them white in the blood of the Lamb’ with the hope of living forever on earth.​—Revelation 7:9, 10, 14, 17; 20:12, 13.