The lay Christian faithful have the right to have recognized that freedom which all citizens have in the affairs of the earthly city. When using that same freedom, however, they are to take care that their actions are imbued with the spirit of the gospel and are to heed the doctrine set forth by the magisterium of the Church. In matters of opinion, moreover, they are to avoid setting forth their own opinion as the doctrine of the Church.
Source: Code of Canon Law (Vatican.va)