I spent some time reading all of the links posted here and it appears that the pastor in the article broke faith with his Lutheran denominational rules by appearing at an interfaith gathering which gave the appearance of condoning (or, at least not disputing) other religions. As you thought I might, I do not understand this position and can find no relevant Biblical reference that specifically can be interpreted to admonish the act of this pastor. Instead, I'm assuming the concern has more to do with doctrinal tenets of the Lutherans which they will back up with their interpretation of a scriptural reference.
Your understanding of my point is right on - religion is what man does to spiritual things. The Pharisees (the Jewish elite) who Jesus never passed on a chance of chastising for their lack of really knowing God, were so critical of Him for being in attendance of prostitutes, gentiles, tax collectors, and other "unclean" persons, that they couldn't see past their noses for who He really was. How dare this man be critical of their approach to their faith! I think His "unconventional" approach so truly po'ed these "religious" leaders that their hearts became hardened towards Jesus and missed the entire point he was trying to make. These "religious" leaders were so caught up in their rulemaking and setting themselves apart from the "unclean" world that Jesus wanted nothing to do with them.
As for the minister who is being threatened with the lost of his ministry, I did some research and came across his defense:
http://www.ad-lcms.org/response_to_charges.html
Sure, it may be self-serving, but I read it with an open mind, and I am absolutely convinced that this man did nothing against his church. To go through this is to "walk a mile in his shoes", and you can certainly understand where he was at physically, emotionally, and spiritually the day he got up to pray in front of people not of his faith. I didn't realize that he was a moving force behind the Nehemiah Plan, I have seen people get houses through that plan, who otherwise would not have had them. Surely, it is as noble a work as Habitat for Humanity. I hope no one here would refuse to pound nails into a house for a needy family, just because the guy working on the other side of the house is from a different church!
In any case, I am convinced that this man is the victim of extreme intolerance, and anyone who could read his side of the story, and feel the same afterwards has a heart of stone.