"There is nothing in my faith that says God will only reveal himself to me and my people," he said. "I can accept that he revealed himself to Jesus, and there is nothing to stop me from believing that he revealed himself generations later to Muhammad."
That does not mean that he should be confused about his own faith, he said. Benedict may have moral authority for Catholics without having the same authority for Christians of other denominations or Jews or Muslims, because God may have given him that authority, but only as leader of the Catholics, Ehrenkranz said.
"He has to interpret the theology for them, but not for me," he said.
When it comes to accepting faiths like Hinduism or Buddhism, which have different conceptions of the role that a supreme being plays in human life, though, he said the question becomes more complex.
"I don't dare say that I know that God revealed himself to them, but if they do not say that God revealed himself to them, then they do not believe in revelation, that's not what they're looking for," he said.
Yale University professor Lamin Sanneh, who converted to Catholicism after growing up a Muslim, said that for him, acceptance of other faiths and respect for people who hold those beliefs is a necessary part of his own faith.
"As a Catholic, it is not my commitment to one way that distinguishes me, it is my commitment to one God that characterizes my belief that all humanity is one," he said.
His faith, he said, is a pilgrimage, rather than an arrival at a static truth, and because of that, there is no cause to exclude another's pilgrimage, even if at least superficially it does not resemble his own. Part of the reason for this, he said, is the commandment not to bear false witness against others.
"I deeply cherish Islam for Muslims, therefore I deeply hope that all of us, Christians, Muslims and Jews, can manifest something of grace in ourselves," he said.
The call of his faith, he said, is such that he must see a bit of God in each human being.
That feeling is familiar to some who say that they cannot accept that faiths other than their own have equal validity. A belief that others are in error in their faith does not mean that you do not respect the person or care about them, they say.
Just as when you see someone doing something that you know will hurt them you try to stop them, so when you see someone whose belief is taking them on the wrong path, you try to set them straight.
"I believe their faith is in error and is false and will ultimately lead to their eternal damnation," said Dan Akin, president of the Southeastern Baptist Theological Seminary. "I have compassion and pity for them, and that's why our seminary sends graduates in missionary work around the world."
There is a line between the political and the social, on the one hand, and the religious, on the other, he said. As an American, he deeply believes in everyone's right to their own religion, and he said he "would die" for that right. As an evangelical Christian, however, he said, he believes it is his duty to try to show others what he sees as the truth.
"If the resurrection of Jesus is truth, then Christianity is true," he said. "If it is not, then I'm a fool. But if it is true, then every other religion is false."