Catholic Cardinal Gerhard Muller, who heads the Vatican's office for the Doctrine of the Faith, said divorced and remarried couples must live in continence, as brother and sister, if they want to receive Communion at Mass and this teaching cannot change -- not by a Pope, an angel, a council of bishops, "no power on Heaven or on Earth."
Cardinal Muller explained this point in an interview with the Italian magazine Il Timone, portions of which were translated into English in the newspaper L'Espresso and re-published in the Catholic Herald. The topic is controversial now because of Pope Francis's letter Amoris Laetitia, which not a few bishops have proclaimed permits the divorced/remarried, who are living as man and wife, to receive Communion, although they are objectively in a state of adultery, a grievous sin.
In the interview, Cardinal Muller is asked, "The exhortation of Saint John Paul II, Familiaris Consortio, stipulates that divorced and remarried couples that cannot separate, in order to receive the sacraments must commit to live in continence. Is this requirement still valid?"
http://www.cnsnews.com/blog/michael-w-chapman/vaticans-muller-no-communion-divorcedremarried-not-evan-pope-can-change