To the “churches” – first (the Tree of Life), Verse in image (Revelation 2:7).

The rest from the “nations” get the “leaves” of the “tree of life” for “healing”.

“in the middle of its street. On either side of the river was the tree of life, bearing twelve kinds of fruit, yielding its fruit every month; and the leaves of the tree were for the healing of the nations.” (Revelation 22:2, NASB)

Why do they need “healing”?

Some of these righteous are from the “second resurrection” (Matthew 25:31 – 46, John 5:28 – 29, Daniel 12:2, Revelation 20:5) as opposed to the “first Resurrection” (Revelation 20:4 – 6, Luke 20:34 – 36) and may require healing.

The difference is that those from the “first resurrection” (1 Thessalonians 4:14 – 17, Revelation 20:4 – 6) are “immortals” (Revelation 20:6, Luke 20:36) who already reigned with Christ for a thousand years and don’t need healing (John 6:35, John 4:14) while those from the “second resurrection” may have age-during life first in their resurrected body (John 5:28 – 29) from the time of the Great White Throne Judgment toward them (Matthew 25:31, Revelation 20:11 – 15).

Second Resurrection of the righteous (John 5:28 – 29, Daniel 12:2, Matthew 25:31 – 46, Revelation 21:24 – 27, Luke 14:14) = (are the righteous from the nations, sheep of the other fold, the sheepfold2, John 10:16). Inclusive of those who BELIEVED after SEEING Him in the afterlife too (John 6:40, 1 Peter 3:18 – 19).

First Resurrection of the righteous (Revelation 20:4 – 6, 1 Thessalonians 4:14 – 17) = those who had “faith” in Christ, believers on earth, His Church, His Bride, the sheepfold1, John 10:14. Those who BELIEVED in Him WITHOUT SEEING or BEFORE SEEING Him, “faith” (Hebrews 11:1, John 6:54, contrasted in John 20:29 too).

Please note carefully a ‘missed’ point in popular theology that the resurrection in both John 5:29 and Daniel 12:2 does NOT refer to “Christians” simply because we do NOT rise with the ‘rest of the dead’ (Revelation 20:5) but have been Resurrected 1000 years EARLIER in the First Resurrection (Revelation 20:4 – 6).

So, since both John 5:29 and Daniel 12:2 describes a resurrection where both the “good and wicked” are ‘resurrected together’, it must refer to a different (second) resurrection from the first resurrection (Revelation 20:4 – 6) where it is based on good deeds vs evil deeds as Lord Jesus Christ mentions in John 5:28 – 29.

Yes, believers (sheepfold1) have their names Written in the Lamb’s Book Of Life but Matthew 25:31 – 46 points to the righteous from the nations too who did “good deeds” (e. g. ‘fed Me when I was hungry, John 5:29, Luke 14:14) toward His “Brethren” (which refers to sheepfold1, His Church, Hebrews 2:11 with Matthew 25:40) who also have their names in the Lamb’s Book Of Life (Matthew 25:34, Revelation 21:27, Revelation 20:15).

P/S: How can one lose their share of the “Tree of Life”?

“and if anyone takes away from the words of the book of this prophecy, God will take away his part from the tree of life and from the holy city, which are written in this book.” (Revelation 22:19, NASB)

How about those wicked who are resurrected for judgment first?

They will have to undergo Judgment (1 Peter 4:5) into the Lake of Fire first (Revelation 21:8, Revelation 20:15) to the age (Matthew 25:46) but will “live to God in spirit” thereafter (1 Peter 4:6) after their perishable body + soul is destroyed in Gehenna Fire (Hebrews 10:27, Luke 12:49) which exists in the Lake of Fire as the Second Death now (Matthew 10:28, Revelation 20:14) where they will be given a “spiritual body” (spirit + body) later accordingly (1 Corinthians 15:44, 1 Corinthians 15:38) as the promise toward the “wicked” too (Acts 24:15) to be RESURRECTED in an IMPERISHABLE SINLESS body too (1 Corinthians 15:50, 1 Corinthians 15:53) as part of “being made ALIVE by CHRIST eventually” (1 Corinthians 15:21 – 22) as Promised toward “all men” (Romans 5:18 – 19) especially believers (1 Timothy 2:4 – KJV, 1 Timothy 4:10) where even the LAW BREAKERS of ‘any Law and Prophets’ (Matthew 5:18) will be made to ENTER His Kingdom eventually (Matthew 5:19) but will NOT inherit it as KINGS nor PRIESTS (1 Corinthians 6:9 – 10)

ONLY the CHRISTIAN RIGHTEOUS both ENTER (Acts 14:22) and INHERIT His Kingdom as KINGS and PRIESTS (Revelation 1:6, Revelation 5:10) toward those from the first resurrection, (sheepfold 1, Revelation 20:4 – 6) while the righteous from other nations (sheepfold2, Matthew 25:33, Acts 10:35, Revelation 22:12) inherit other lower positions or possessions as God Wills (Matthew 25:34).

The wicked being Saved from the Lake of Fire itself is Beautifully Prophesied in Verse below where both His Spirit (God) and His Bride (“believers”, Church) call out to “thirsty ones from the Lake of Fire (implied)” to partake of the “Water of Life” freely:

“The Spirit and the bride say, “Come.” And let the one who hears say, “Come.” And let the one who is thirsty come; let the one who wishes take the water of life without cost.” (Revelation 22:17, NASB)

The above event is not immediate but eventually (after the wicked have their part accordingly in the Lake of Fire first, Revelation 21:8) as it is PROPHETICALLY echoed in Verse above.

Only the Righteous may enter into the Holy City (Revelation 21:27, Revelation 22:14) while the wicked may be “outside” only (Revelation 22:15) during that Time of Judgment.

Peace to you