As this week's Newsweek cover article insists, heaven is a powerful and pervasive word. It has been used to motivate people of many faiths in many ways: To instill character and strengthen resolve. To build community and spur change. To steel terrorists and comfort victims. It is easy to imagine this word, as the writer of the Newsweek article does, on the lips of both the hijackers of American Airlines Flight 11 and many of the passengers.

Apparently, although ministers in mainline Christian churches in America don't preach much about heaven, 75 percent of Americans believe they'll go there—if they're good. Evangelicals talk more about the subject, believing that only faith in Christ can put them on the "highway to heaven." And most folks expect that once through the gates, they will see not only their Lord, but also their loved ones (for some, including their pets).

For thoughtful Christians, all of this raises the question, "What did the early church believe about heaven?" The answer draws together both divine communion and human reunion.

For the apostles, heaven-as-divine-communion was a given. Indeed, in the New Testament the word "heaven" is often used to stand for God himself (Luke 15:21; Matt. 21:25, 23:22; John 3:27).

But heaven was a place, too. As Jesus had promised, "I go to prepare a place for you … that where I am you may be also" (John 14:3-4). And this place was not simple, but rather a complicated space with rooms or levels (an idea the great Italian poet Dante Alighieri would expand upon to unforgettable effect over a millennium later). In 2 Corinthians 12:2-4, the Apostle Paul pulls perhaps the biggest tease of the Bible when he tells of being lifted up into "the third heaven," where he experienced "things ...