What's a synod?
It's an organized meeting of bishops. The Catholic Church views itself as being led not just by the pope, but by the pope in communion with the bishops, who are the successors of the apostles appointed by Jesus to lead the Church. In other words, the bishops are a real source of authority in the Catholic Church. Even though under canon law the synod cannot decide anything without the approval of the pope, in practice a synod is an important meeting where things can happen. And it can last for many, many days.
What's the biggest issue being discussed at the synod?
Communion for divorced and remarried couples. According to Catholic doctrine, the Eucharist, or Holy Communion, is the real presence of Christ. What appears to be bread and wine is the body, soul, and divinity of Christ, which believers receive as a way of drawing closer to Christ. This makes it a pretty big deal. And because it is such a big deal, the Catholic Church says that those who have a serious sin on their conscience cannot receive Holy Communion.
One such group of people are couples who were previously married, got divorced, and then remarried. According to the Catholic Church, divorce is, strictly speaking, impossible, and so someone who gets a civil divorce and then gets remarried is really in a state of adultery against the first spouse. He or she thus cannot receive Communion.
But given the undeniable and massive reality of divorced and remarried couples, some people have suggested relaxing this rule to allow some divorced-remarried couples to receive Communion after doing penance.
Is a major change likely?
Probably not. The issue seems to be too strongly tied to the Bible and the teachings of Christ himself to be changed. And there would be a historic dissonance. If someone can get a divorce and a remarriage and still be in full communion with the Church, then what was all the English Reformation about? Did all those Catholic martyrs die for nothing?
The Church draws a distinction between "doctrine," which cannot ever be changed, and "discipline," which is the application of doctrine to various situations and can be changed. This issue seems to be one of doctrine.
So what's going to happen?
I would wager that the Church will try to get around this by relaxing the rules to get an annulment. An annulment, technically speaking, is not a divorce; it is a recognition that because a marriage was attempted without the basic requirements, such as full and informed consent, there was really no marriage to begin with and one is free to remarry.
Annulments are a touchy issue. Some say that in some places in the world, the process has become so lax that it's basically just a "Catholic divorce." But in many other places, the process is so bureaucratic and time-consuming that couples with genuine cases can never get to the end of it.
Is divorce the only issue facing the synod?
That's the impression you might get from the media. But there's plenty more being discussed.
The divorce issue is being played up for a few reasons. First, because it sounds like a "thing" where the Catholic Church might actually change something, which is always a huge deal in Catholicism. And second, because there is a perception that Pope Francis might be more amenable than his predecessors to changing Church rules, and so a lot of people are expecting him to do something in this regard.
But in reality, the synod is meant to address all issues related to the family: that people are marrying later, are cohabiting more, that divorce in general remains high, that many married couples use contraception, and so on.
The issue of divorced-remarried couples has also been played up for another reason: It's very Western. But the Catholic Church is a global Church. In many parts of the world, the bigger issues that bishops have to confront relating to the family are things like polygamy or arranged marriage.
So...what does Catholicism say about the family?
The central thing Catholicism says about the family is that it is an institution God created to teach us about his love. (In fact, everything on Earth is created to teach us about God's love.) One of the central doctrines of Christianity is the Trinity: that there is one God, existing eternally in three divine Persons, in a permanent relationship of self-giving love. And so we have received this gift of the family to learn what self-giving love is like: the self-giving love of complementary spouses to each other, the self-giving love of parents for children and siblings for each other, and so on.
Another central doctrine of Christianity is the Cross: that God loves us so much that he became a man and was willing to die to save us. In other words, what distinguishes Catholicism's view of the family is this element of the recklessness of love: a love that goes all the way if it has to. Love, God teaches us, is a great cosmic roll of the dice. And so are our mortal lives. The reason why divorce is thought to be impossible, or why couples should have as many children as God will give them, is not because of some reactionary view but because our love should be like God's love: totally committed and fruitful, to the point of recklessness, and even folly.
Obviously, we all know people, and indeed are people, who fall far short of that lofty ideal, and another central doctrine of Christianity is that we are all sinners in need of forgiveness.
The synod clearly has its work cut out for itself.