You nailed it.

therefore drinking is spiritual.

This is the kind of bullshit logic many religions adopt to get from A to B; where A is something innocuous sounding and B is something that sounds profound. It works because thinking is contaminative. In the above example, there was a simple conflation of the concepts behind the words "spiritual system" and "spiritual." Most people won't pick up on that because the two words sound very similar.

Thus, in getting from A to B via a sequence, C,D,E..., all you have to do is slightly change the meanings of the words (or use similar sounding words) in each step of the argument. By the time you reach B, you can could've proved whatever you wanted.