[Land of the Irish]

Nope, I don't think he is talking about political socialism, or left-wing defined humanism, or syncretism of the Catholic Faith with other religions.

Then what is he talking about? The Social Reign of Christ the King?

I think not.

[TotusTuus]

Then what is he talking about?

I think it's along the line of sending a message to participants in a meeting to be held among various churches (including representatives of the Catholic Church), ecclesial communities, and other major world religions.