Israel was not simply a modern state church
Israel in the Old Testament was both a people bound to God by covenant and a nation with its own laws, worship, priests, and kings. The law given through Moses shaped public life as well as personal devotion. That arrangement was real, but it belonged to Israel's particular calling among the nations (Deuteronomy 7:6).
It does not automatically provide a blueprint for every later government. Israel's worship centred on the temple in Jerusalem and the priesthood descended from Aaron. Christians believe Jesus fulfils the law and opens God's people to Jews and Gentiles alike, rather than forming one new earthly nation with a Christian ruler (Galatians 3:28-29).
For thou art an holy people unto the Lord thy God: the Lord thy God hath chosen thee to be a special people unto himself, above all people that are upon the face of the earth.
Jesus did not seek political rule
When Pilate questioned Jesus, Jesus made clear that his kingdom was not from this world (John 18:36). He is truly King, but he did not call his followers to seize the Roman state or make Rome enforce Christian worship. His reign changes lives and forms a people from every nation.
Jesus also distinguished what belongs to Caesar from what belongs to God (Mark 12:17). Government has a proper sphere, yet no government can claim the worship, conscience, or ultimate allegiance that belong to God. That distinction matters whether a government is friendly, hostile, or somewhere in between.
Jesus answered, My kingdom is not of this world: if my kingdom were of this world, then would my servants fight, that I should not be delivered to the Jews: but now is my kingdom not from hence.
The church has a different kind of authority
The New Testament churches spread through witness, prayer, service, teaching, and costly love. Paul described believers' weapons as spiritual rather than fleshly, which rules out treating political force as the church's main means of advancing Christ's work (2 Corinthians 10:3-4). Faith cannot be manufactured by a law.
Church leaders are called to serve willingly and humbly, not to dominate those in their care (1 Peter 5:2-3). This does not mean Christians must withdraw from public life. They can vote, serve, speak for justice, and work for their neighbours' good. But the church's calling is not the same as holding state power.
Honour rulers, obey God
Paul told Roman Christians to recognise governing authorities, since civil order can restrain wrongdoing and promote peace (Romans 13:1-4). Christians can pray for rulers and seek the welfare of the places where they live. A government does not need to be officially Christian for believers to practise this faithful public responsibility.
Still, human rulers are not final. When the authorities ordered the apostles to stop speaking about Jesus, Peter and the others said they must obey God rather than men (Acts 5:29). So a state church may be a historical arrangement some Christians have supported and others have opposed, but Scripture does not require it. The clearest biblical pattern is a church devoted to Christ, free to worship and witness, while respecting civil authority without confusing it with God's kingdom.
Then Peter and the other apostles answered and said, We ought to obey God rather than men.