…and on either side of the river, was the tree of life…The leaves of the tree were for the healing of the nations…Blessed are those who do His commandments that they may have the right to the tree of life, and may enter through the gates into the city. – Revelation 22:2,14

Amongst the fancies of idolatry are there any inventions of man that can cool his fevered brow and sooth his griefs? Does Mohammedanism offer hopes for eternity that can light up the grave to an awakened sinner? Are there thoughts of bliss in idolatry calculated to cheer the sepulcher? All religions answer, “Comforts are not in us.” It is only at the cross, it is only by Jesus crucified that the world can be healed. Hitherto little has been accomplished compared with our desires; and in contrast to our ambitions, next to nothing; but faith, darting beyond the things that are seen, flying into the presence-chamber of God, can behold Him writing with the eternal pen, “All flesh shall see the salvation of God.”

We have sweetened the waters a little; no more the suttee burns; the African is free; the slave-ship crosses no more the deep. In some regions exterminating wars have ceased; the white dove of peace flies where the raven of war was seen. Glory be to God. A few leaves cast into the waters have done this. Let us bear a whole Christ and a whole gospel amongst the nations, and lay the tree in this Marah, until at last the whole world shall drink of the sweet waters of divine love, and God shall be all in all. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/0987.cfm