The Dismissal of Earthly Jerusalem as Spiritually Significant
Jesus said to her, “Woman, believe me, the hour is coming when neither on this mountain nor in Jerusalem will you worship the Father.  You worship what you do not know; we worship what we know, for salvation is from the Jews.  But the hour is coming, and is now here, when the true worshipers will worship the Father in spirit and truth, for the Father is seeking such people to worship him.  God is spirit, and those who worship him must worship in spirit and truth.” – John 4:21-24
Here, for the first time in the history of history, God tells us that earthly Jerusalem will no longer retain spiritual significance. Jesus tells us the time for that truth had arrived. That hour “is now here”. Under the Gospel, earthly places like Jerusalem no longer hold distinction as a spiritual place of worship. The time when men were to go to the temple in Jerusalem, attend feasts and observe outward ceremonies under the old covenant were now forever dismissed with the death, resurrection and ascension of Jesus to the Father, with redemption of the elect now completed. God is seeking worshippers from every place, from every tribe and tongue to worship Him. Where one worships is no longer spiritually significant, the important thing is how, in “spirit and truth.”
In regards to this passage, John MacArthur notes the following in his study bible:
4:20 on this mountain. Both Jews and Samaritans recognized that God had commanded their forefathers to identify a special place for worshipping Him (Deut. 12:5). The Jews, recognizing the Hebrew canon, chose Jerusalem (2 Sam. 7:5-13; 2 Chr. 6:6). The Samaritans, recognizing only the Pentateuch, noted that the first place Abraham built an altar to God was at Shechem (Gen. 12:6,7), which was overlooked by Mt. Gerizim, where the Israelites had shouted the blessings promised by God before they entered the Promised Land (Duet. 11:29,30). As a result, they chose Mt. Gerizim for the place of their temple.
4:21 neither on this mountain, nor in Jerusalem. There was no reason to debate locations, since both places would be obsolete soon and neither would have any role to play in the lives of those who genuinely worship God. Jerusalem would even be destroyed with its temple in 70 A.D. (italicized emphasis mine).
In one fell swoop, our Lord Jesus lets every child of Zion know with certainty, the entire company of the redeemed by way of the Gospel, that the spiritual significance of earthly Jerusalem in Palestine, along with the spiritual significance of every nation, is obliterated forever. Under the New Covenant, through the preaching of the Gospel of Jesus Christ and the effectual calling of God, peoples from every tribe and tongue join the mystical community of faith, the Church! Glorious truth!