What is the fountain of the water of life in Revelation 21:6?

In Revelation 21, the apostle John sees the New Jerusalem, with the redeemed and resurrected believers dwelling in God’s everlasting presence (verses 1–3). God tenderly wipes away every former sorrow and pain in this newly created heaven and earth (verse 4). From His great heavenly throne, Jesus Christ speaks to John, saying, “It is done! I am the Alpha and the Omega, the Beginning and the End. I will give of the fountain of the water of life freely to him who thirsts” (Revelation 21:6, NKJV).

To all who are thirsty, Jesus offers an endless supply of drink from the fountain of living water at no cost. This reality becomes a mantra echoing back and forth throughout Scripture as the Lord gives His invitation to salvation and eternal life with Him. The prophet Isaiah conveyed the offer:
In His famous Sermon on the Mount, Jesus said, “Blessed are those who hunger and thirst for righteousness, for they will be filled” (Matthew 5:6). Thirst in Scripture is often a picture of human spiritual need. The fountain of the water of life is reserved for those who recognize their thirst and need for God’s salvation (Isaiah 12:2–3; 41:17–18; Psalm 42). A drink is not given to everyone, but only to those who believe and place their faith in Him (Acts 16:30–31; John 6:35; 7:38). No one accidentally drinks from the fountain of living water.

To the woman who came to draw water from the well, Jesus explained, “Anyone who drinks this water will soon become thirsty again. But those who drink the water I give will never be thirsty again. It becomes a fresh, bubbling spring within them, giving them eternal life” (John 4:13–14, NLT). On the final day of the Feast of Booths, Jesus declared, “Anyone who is thirsty may come to me! Anyone who believes in me may come and drink! For the Scriptures declare, ‘Rivers of living water will flow from his heart’” (John 7:37–38, NLT).

The fountain of the water of life is a free gift (Ephesians 2:4–9; Romans 3:21–24). No one can buy a place at the fountain or work his way into heaven (Romans 11:5–6; Titus 3:4–7). God the Father is the source of this gift of life. He is “the fountain of life” who gives us “drink from [His] river of delights” (Psalm 36:8–9). The prophet Jeremiah recognized that those who turn away from Him are forsaking “the fountain of living water” (Jeremiah 2:13; 17:13, ESV).

Out of His great love and mercy, God gave His Son, Jesus Christ, to be our fountain of the water of life and supplier of eternal life (John 3:16–17; 11:25–26; 17:3; Romans 6:23). He is the “spiritual rock” from whom we drink life-giving “spiritual water” (1 Corinthians 10:3–4).

The Great Awakening preacher Jonathan Edwards wrote, “Christ is like a river. . . . A river is continually flowing, there are fresh supplies of water coming from the fountain-head continually, so that a man may live by it, and be supplied with water all his life. So Christ is an ever-flowing fountain; he is continually supplying his people, and the fountain is not spent. They who live upon Christ, may have fresh supplies from him to all eternity; they may have an increase of blessedness that is new, and new still, and which never will come to an end” (Edwards, J., The Works of Jonathan Edwards, vol. 2, Banner of Truth Trust, 1974, p. 932).

In the restored Eden of the New Jerusalem, the fountain of the water of life becomes an everlasting river of life, flowing clear and bright from the Lord’s throne through the Holy City (see Revelation 22:1). As Revelation concludes and the Bible comes to a close, John hears the Spirit and the Bride say, “Come,” in God’s final, resounding invitation: “Let anyone who is thirsty come. Let anyone who desires drink freely from the water of life” (Revelation 22:17, NLT).