The Second Vatican Council in the twentieth century also upheld the indissolubility of marriage "clearly and distinctly" in the pastoral constitution "Gaudium et Spes."
"Marriage is understood as an all-embracing communion of life and love, body and spirit, between a man and a woman who mutually give themselves and receive one another as persons," the archbishop said. The indissolubility of marriage "becomes the image of God's enduring love for his people and of Christ's irrevocable fidelity to his Church."
The archbishop noted that the Church has defended the indissolubility of Christian marriage "even at the cost of great sacrifice and suffering." The schism of the Anglican Church came because the Pope's obedience to Jesus "could not accommodate the demands of King Henry VIII for the dissolution of his marriage."
Orthodox Christian Churches, he said, have allowed "a great many grounds for divorce" on the grounds of "pastoral leniency." However, he was critical of the practice, saying it "cannot be reconciled with God's will" and "represents an ecumenical problem that is not to be underestimated."
The archbishop warned that the modern mentality is "largely opposed" to the Christian understanding of marriage, its indissolubility, and its openness to children. This means contemporary marriages are "probably invalid more often than they were previously" and so assessment of whether a previous marriage was valid is "important" and can help solve problems.
Archbishop Müller acknowledged that care for the divorced and remarried is a pastoral problem of "significant dimensions." However, he said that care for remarried divorcees cannot be reduced to the reception of the Eucharist. Rather, they should be encouraged to turn to God.
"God can grant his closeness and his salvation to people on different paths, even if they find themselves in a contradictory life situation," he said. "As recent documents of the Magisterium have emphasized, pastors and Christian communities are called to welcome people in irregular situations openly and sincerely, to stand by them sympathetically and helpfully, and to make them aware of the love of the Good Shepherd."
He pointed to Bl. Pope John Paul II's 1981 apostolic exhortation "Familiaris Consortio" as an example of pastoral concern for remarried divorcees. Pope Benedict XVI also addressed their situation in his 2007 apostolic exhortationn "Sacramentum Caritatis."
Archbishop Müller also cited the October 2012 Synod of Bishops, whose concluding message addressed remarried divorcees.
"To all of them we want to say that God's love does not abandon anyone, that the Church loves them, too, that the Church is a house that welcomes all, that they remain members of the Church even if they cannot receive sacramental absolution and the Eucharist," the synod said. "May our Catholic communities welcome all who live in such situations and support those who are in the path of conversion and reconciliation."