For the International Church of Cannabis in Denver, there were three reasons to celebrate on Thursday.

First, it was opening day. The church, a more than century-old building recently adorned with brightly colored paintings by the artists Kenny Scharf and Okuda San Miguel, welcomed the public early in the afternoon, at which time no cannabis consumption was allowed inside.

“It seemed to be a nice steady flow of people,” said Lee Molloy, a founder of the church and a member, who estimated that a couple of hundred people had come by.