Christian nations displaced national Israel, according to Amillennialists. And in our time the entire idea of a "Christian nation" has now been completely rejected by many Amillennialists. For them, Israel can never become a Christian nation because "there is no such thing as a Christian nation at all!"
Apart from the Holy Church, there is no Christian "nation".
"But you are a chosen people, a royal priesthood, a holy nation, God's special possession, that you may declare the praises of Him who called you out of darkness into His wounderful light." - 1 Peter 2:9
She is a nation of migrants, wanderers, wayfarers, strangers here; for our πολίτευμα is in the heavens, where Christ reigns; we have been birthed as children of a different kingdom, one where the least are greatest, shaped not like a sword, but a cross. For God is King, and through His Holy Messiah He rules; all the kingdoms of this world are subject to the supreme authority and Lordship of the Messiah, and that is why every knee will bow and every tongue confess that Jesus Christ is Lord to the glory of God the Father. All kings shall be judged as mere men; and the kings of the earth who have acted wickedly shall have their share of the deepest pit,
"Your pomp is brought down to Sheol,
the sound of your harps;
maggots are laid as a bed beneath you,
and worms are your covers." - Isaiah 14:11
Therefore
"the kingdoms of this world are become the kingdom of our God and of His Christ, and He shall reign forever and ever." - Revelation 11:15,
"Then the iron, the clay, the bronze, the silver, and the gold, all together were broken in pieces, and became like the chaff of the summer threshing floors; and the wind carried them away, so that not a trace of them could be found. But the stone that struck the image became a great mountain and filled the whole earth" - Daniel 2:35
"Then comes the end, when He delivers the kingdom to God the Father after destroying every rule and every authority and power. For He must reign until He has put all His enemies under His feet. The last enemy to be destroyed is death." - 1 Corinthians 15:25-26
"YHWH said to my Lord, 'Sit at My right hand, until I make Your enemies Your footstool.'" - Psalm 110:1
The one Christian nation is the nation made up of all nations, tribes, and tongues; birthed of God by His grace, for there is one new man. She is without borders, she has no princes nor masters except the one Lord Jesus Christ. She is a nation in, but not of, the world; and who makes her habitation in the many kingdoms of this world, declaring her foreign allegiance to the King of kings; while still serving her neighbor, paying her taxes, praying for princes and kings and emperors, as she fears God.
-CryptoLutheran