the elusive link -- religious experience

Several years ago Luke Timothy Johnson called out the neglect of religious experience among students of early Christianity in his Religious Experience in Earliest Christianity: A Missing Dimension in New Testament Studies. In the interim several attempts to explain the spread of early Christianity have emerged, usually with sociological frameworks.

For my part, 1 Thessalonians 1:5 has long arrested my attention. Recalling his first visit among the Thessalonians, Paul writes, "our message of the gospel came to you not in word only, but with power and the Holy Spirit and full conviction."

I take Paul seriously here. Paul is calling the Thessalonians to recall the basic religious experience they shared during Paul's visit. In fact, he devotes most of the letter to this very subject. Apparently, he's trying to maintain a positive relationship with this church he has not seen in a long time. His task, then, is like that of a lover writing a letter to the beloved. She or he had better not overstate how great things were when they were last together; otherwise, the whole enterprise is in trouble. I imagine that Paul actually recalls a shared and powerful religious experience from that first visit.

What I'd love to know is, what does Paul mean by power? What sort of religious experience lies behind this? As we consider how early Christianity spread, let's not shut down our imaginations to the work of religious experience.