Communism, or preferably Socialism, would work if it could be done properly, ie from the bottom up. Top-down, centralised power structures meant that the system became, functionally, Fascist. Properly speaking, Socialism should devolve as much power as possible to the local, community-based level, with the regional and national superstructures having severely limited powers and responsibilities.

In Christianity, there is a Biblical injunction to 'make disciples of all nations'. This probably meant that the opportunity to become a Christian should not be denied to anyone on grounds of nationality or ethnicity (in the early days, some Christians believed you had to be Jewish to join). But it has been used by Dominionists to justify proselytism.

A distinction needs to be drawn between evangelism, which is preaching ones' faith in the hope of gaining converts, and proselytism, which is the act of gaining converts by any and all means including force.