The communal life of the early Christian communities and of monasteries is not communism as it is commonly understood. It is not based on an ideology but on loyalty and devotion to God and the Christian ideals of charity,unity,prayer,service and poverty.
Communism is entirely bad. It is a materialistic ideology that denies the right to private property,which is part of God-given natural law. It fosters resentment towards the prosperous for being prosperous,and covetousness towards their property. This is an attitude that has no place in Christian morality.
The Catholic author Malachi Martin,who was a Jesuit,wrote a book entitled The Jesuits,in which he describes the infiltration of marxists and socialists into the Jesuit order during the 1950’s and 1960’s.