You have to make a case that we can't love our neighbors in place. In other words, if we maintain our cultural soundness here, and if our freedom and prosperity excels (as it should), then we can share what we build by helping others in their own countries. If we bring too many people from different cultures here, and I think we have, then we will face a problem with assimilation. The philosophy that all cultures are equal has already permeated our media and our university campuses; it's filtering down to our lower grades and such, as well. That notion is that Christianity offers no special rewards. Think about it: your Christian taxes are being spent to deny your own beliefs not by removing Moore's slabs, but by teaching children in school and youngpeople in universities that Marx and Derrida have more to offer than absolute morals.
We can help the world better if we help ourselves first. I see nothing unchristian about that at all.
All we have and all we are come from Christ. He gave us simple commandments to follow with simple warnings. It is our duty to follow Christ by loving our neighbor, God will take care of the rest. The fear you have is because you do not know Christ.