6 As against this, Christian Democracy, by the fact that it is Christian, is built, and necessarily so, on the basic principles of divine faith, and it must provide better conditions for the masses, with the ulterior object of promoting the perfection of souls made for things eternal. Hence, for Christian Democracy, justice is sacred; it must maintain that the right of acquiring and possessing property cannot be impugned, and it must safeguard the various distinctions and degrees which are indispensable in every well-ordered commonwealth. Finally, it must endeavor to preserve in every human society the form and the character which God ever impresses on it. It is clear, therefore, that there in nothing in common between Social and Christian Democracy. They differ from each other as much as the sect of socialism differs from the profession of Christianity.
Source: Graves de Communi Re (Vatican.va)