Pope: Another Second Vatican document rather than an encyclical
Read the Document DIGNITATIS HUMANAE
Summary: Essentially a declaration of religious freedom and the call for all Christians to respect religious freedom, a freedom which must also be permitted by states. The church must be allowed to work freely, but compulsion or force must play no part in a person’s response to God.
Backstory: This was one of the most contentious of all of the Vatican documents with much of the initiative coming from the US church favouring secularism. As a result this was opposed (and still is today) by many conservatives favouring the involvement of the church in the state as was seen in Spain and Italy, and as the church had acted up until the early 20th century.