Christian Nationalism has never been about Christianity - in the sense of following what Jesus taught. If you assume that a Christian Nationalist will answer your question honestly, which is a bad assumption, then the answer would be control of the country by political means. Christian Nationalism is just like all the other empire-like ideologies before it. It is most concerned with control and power. It is grounded on a creed of the ends justify the means, might makes right, and the strong survive.