Christianity was a fine religion back during pre-industrial times, where the "foreigner" to be treated with compassion was generally just some guy from the next village over.
Universalism wasn't a dysgenic position when it wasn't possible to couldn't ship the entire third world to your country via planes and boats.
For these modern times, we need something that provides the toolset to preserve our ethnicities.
But what could it be?

The truth and the truth alone

Christianity is what stopped European colonizers from killing off all the non-White races. Instead of killing the subhumans they converted them to Christianity.