Krister Stendahl died earlier this year (hat tip: Lehi’s Library).
He was a Swedish scholar and theologian, and also served for a period
as the Lutheran Bishop of Stockholm. In LDS circles, he is fondly
remembered as the author of three rules of religious understanding,
which he propounded during public debate critical of a planned LDS
temple in Sweden. They are good rules to follow in any religious or
interfaith conversation. Here are Stendahl’s three rules.

• When you are trying to understand another religion, you should ask the adherents of that religion and not its enemies.
• Don’t compare your best to their worst.
• Leave room for “holy envy.” (By this Stendahl meant that you should
  be willing to recognize elements in the other religious tradition or
  faith that you admire and wish could, in some way, be reflected in your
  own religious tradition or faith.)