I see this as more of a failure of the city's zoning code than anything. I have a lot more of an issue with the parking lot at that spot than tearing down the church. The city has zoning "districts" where they want to encourage certain developments, but do little to make sure that that happens. If the zoning code didn't allow for a parking lot there, which it clearly shouldn't, this problem wouldn't arise in the first place.
Interesting stuff. It'd also be interesting to see how these Maine cities compare to comparable cities in states like New Hampshire and Massachusetts.
You can make any argument you want about whether that building is unsafe or not. The bottom line is that vacant church means a lot more to the city vacant than surface parking does on that lot. It would be a disgrace if parking was put there, in the midst of Lewiston's most urban district. That is a valuable spot that needs to be used for anything BUT parking. If that meant just some abandoned church as a historic monument, I'd pick that over a parking lot any day.