Editors' Note: This article is part of the Public Square 2014 Summer Series: Conversations on Religious Trends. Read other perspectives from the Catholic community here.

Brandon Vogt interviewed Cardinal Thomas Collins, who sheds light on many of these issues. This interview first appeared at Word on Fire Catholic Ministries, and is reprinted here with permission.

Vogt: Much of the current discussion about divorce, remarriage, and communion is clouded by confusion. What does the Church actually teach on these issues and why?

Cardinal Thomas Collins: The Catholic Church simply teaches what Jesus teaches: marriage is an unbreakable covenant between a man and a woman, faithful in love and open to the gift of life. Divorce and remarriage is not allowed when it is a matter of a valid, sacramental, and consummated marriage.

When Jesus was preaching in Galilee, divorce and remarriage was accepted in society. The law of Moses allowed for it (Deuteronomy 24:1-4). The teaching of Jesus that divorce and remarriage is not allowed was revolutionary. It was even an indication of his claim to divinity, for only God has the authority to overrule the law of Moses. Jesus went back to creation itself for the foundation of the unbreakable bond of marriage between a man and a woman: "Have you not read that from the beginning the Creator 'made them male and female' and said, 'For this reason a man shall leave his father and mother and be joined to his wife, and the two shall become one flesh.' So they are no longer two, but one flesh. Therefore, what God has joined together, no human being must separate" (Matthew 19:1-12). In light of current controversies, it is also helpful to note that Jesus also asserts plainly something that until recently was obvious to everyone: marriage is between a man and a woman.

It is always assumed by the Church that couples are truly, or "validly," married. The burden of proof is on anyone who says that they are not. When requested, however, the Church will examine a marriage to discover whether it was a truly binding commitment of the type that Jesus is talking about, i.e., a valid marriage, which cannot be dissolved. If, after very careful study, the Church discovers that at the time when they exchanged consent at their wedding the couple for some reason did not truly make a binding commitment to marriage, then it will issue a statement, or "declaration of nullity," officially confirming that the marriage was not "valid" from the start. This is very different from a divorce, in which the government official grants that there was a valid marriage, and then uses the power of the state to end it.

Some Catholics hope the Church will soon change her position regarding communion for those who are divorced and remarried, perhaps at the upcoming Synod. Others worry such a change would undercut Jesus' clear teachings on marriage. On this issue, which teachings and practices are immutable and which are open to change?

The Synod on the Family will surely deal with the whole range of issues facing the family today, not only this one issue of communion for those who are divorced and remarried. For example, one of the key problems we face now is that couples are more often living together without getting married. And there are many societal trends, especially in the western world, that undermine the family. The question of communion after divorce and remarriage is one among many issues, and I would imagine that the Synod will spend most of its time on the broader issues affecting marriage and the family.