Swadeshi is that spirit in us which restricts us to the use and service of our immediate surroundings to the exclusion of the more remote.
Thus, as for religion, in order to satisfy the requirements of the definition, I must restrict myself to my ancestral religion. That is, the use of my immediate religious surrounding. If I find it defective, I should serve it by purging it of its defects.
Love is universal while practicing love depends on cultures. So is the relationship between Faith and religions.
Swadeshi applies also to migrants. In their case they need to leave behind their culture and religion and integrate into the culture and religion of the land and of the guardian people of that land.
If it is OK migrants are welcome; but if they don’t like it then they have to stay away and don’t trouble themselves and the established culture. The reason behind it is very logical since they are the best for the receiving guardian nation and developed from ancient experience and wisdom.
This doesn’t mean migrants have to change their Faith, it is only a change of the codes and practices of the Faith.
Cultures and religions are essentially dynamic, but they develop from within, and they interact with the internal and external changes and needs.
Injecting or imposing foreign culture and religion on any nation by immigrants will never result in any health condition or cohesion between the local and the foreign.