“For the Lamb in the midst of the throne will be their shepherd, and he will guide them to springs of living water, and God will wipe away every tear from their eyes.” (Revelation 7:17)
At the beginning of Revelation 7, John records the sealing of the 144,000. Almost all the numbers in this book are symbolic so we are to understand this number to be a symbol of perfection, being a multiple of 12 as in 12 apostles and 12 tribes. The number 144,000 is not to be taken literally as some sects have done. Here it simply means the full number of the redeemed.
This symbolism is confirmed by the fact that what John sees next is a vast uncountable number of people from every tribe and nation, much more than 144,000. These apparently have all faithfully suffered and endured through the great tribulation and received their reward. This idea of sealing from judgment is drawn from Old Testament sources. One of those is Ezekiel 9 where the Lord sent an angel to mark those of His people He would spare from judgment. Those who were not marked by the angel’s seal would be condemned. Another source is Exodus 7-12, the events surrounding the Passover. While the Israelites lived in the midst of the Egyptians the plagues only fell upon the latter because God marked those who were His so they would be saved from destruction.
John’s words were of great comfort to those in his church audience as they are today to all believers. He will protect them during times of persecution and tribulation. Though they may endure severe suffering and even death for their faithfulness to the truth of the gospel, the Lord will never abandon those who are His. The judgments of God will not come near them. They need not fear as those who do not know the Lord.