Matthew 16:25 New International Version
For whoever wants to save their life will lose it, but whoever loses their life for me will find it.
In 1519, Spanish Conquistador Hernan Cortes, facing attempts by some from his expedition to abandon their mission and sail back to Cuba, ordered his entire fleet to be scuttled {The popular story is that the ships were burned, but given how costly they were, Cortes would have only put holes in the ships, making sailing them impossible in the short-term so they could be salvaged at least for the wood later on}. Having eliminated the possibility of retreat, Cortes then led his men onward in the Spanish conquest of Mexico.
An illustration from a conquest carried out, at least on paper, in the name of Christ is not something one would normally use when writing against 'Christian' Nationalism since that's the attitude we need to avoid, but the well known actions of Cortes, in an unjust cause, still serve as a reminder of how differently people act when they have passed the Point of No Return.
Every single legitimate follower of Jesus Christ throughout history was past the Point of No Return from the moment he/she became committed to Jesus until death. What does this mean? This world is not our home, this life is not ours to do with as we please. We are here on a mission from God, called to serve a purpose, we cannot do that and try to live for wealth, power, or fame in this world too.
'Christian' Nationalists certainly have a sense of purpose and mission, that's not the problem, the problem is that they've turned the focus of our calling as Christians toward this world and not the next, toward the physical and not the spiritual. Toward power and control here and now, not the service and sacrifice that Jesus demands of us. In the end, they're still trying to save their lives (and/or country) here rather than give them over to the Gospel.
As the Steven Curtis Chapman song, Burn the Ships, inspired by Cortes' bold move says,
"Burn the ships we're here to stay
There's no way we could go back
Now that we've come this far by faith
Burn the ships we've passed the point of no return
Our life is here so let the ships burn and burn"