The prelate responsible for shepherding the process said one thing is clear: The coming days will see an "opportunity to deal with existential issues."
Cardinal Raymond Burke said Pope Francis can't change current church teaching because he and all bishops "are held to obedience to the truth" about marriage, and that cannot change.
Everyone has a special gift to offer the whole church, just make sure it is used to serve everyone and not to puff up one's own pride or to create division, Pope Francis said.
"It is a gift that God has given to someone not because he or she is a better person than someone else or because she or he deserves it," the pope said Wednesday at his weekly general audience in St. Peter's Square.
Opinion: LGBT Catholics love for the synod to accept same-sex marriages, but they are realistic enough to believe this will not happen. They are thinking of future generations.
A Roman Observer: For his first column, Robert Mickens, a longtime Vatican observer, tells us what to expect when the synod on the family opens this weekend.
Pope Francis warned against the abandonment and neglect of the elderly, calling it a "hidden euthanasia" rooted in today's "poisonous" culture of disposal and an economic system of greed.
In the presence of his predecessor, Pope Francis also thanked retired Pope Benedict XVI for staying to live at the Vatican and being like "a wise grandfather at home."
"A people who don't take care of their grandparents and don't treat them well is a people with no future. Why no future? Because they lose the memory [of the past] and they sever their own roots," he said.
The Vatican formally criticized a U.N. committee's "grave misunderstanding" of state sovereignty and reiterated its concerns over "controversial new expressions" that threaten the unborn and religious freedom.
By insisting the Holy See should enforce the compliance of Catholics all over the world with international treaties signed by the Vatican, the U.N. Committee on the Rights of the Child "offers a controversial new approach to 'jurisdiction,' which clearly contradicts the general understanding of this concept of international law."
A new papal commission is looking at how Vatican media outlets can better communicate the church's message "of healing, of love, of hope, and of generosity of spirit," the panel's leader said.
The group is drawing up "proposals that will recognize the particular importance of what the church is communicating and the way in which it can best communicate that message in the 21st century," said British Lord Chris Patten, commission president.
Excitement and anticipation for this synod have been high, partly because of a survey the Vatican sent to the world's bishops last year.
For years, they have been invisible and often afraid to identify themselves. But the women sometimes dubbed "God's rivals" are no longer willing to remain silent.
Twenty-six Italian women who are married to or in relationships with Catholic priests want clerical celibacy to be overturned by the world's bishops when they meet in Rome for their global synod on the family in October.