Lewis spent much of his life writing books that were supposed to help people persuade other people to convert, and it is quite certain that nearly all of the pestering Lewis was familiar with was done in the name of his own God. I find it unlikely that, if an army of Lewis clones were made rulers of England, they would allow gay marriage, prostitution, and polygamy.
The name of the book is God in the Dock because it is about accusations against God--and this is most properly an accusation against the Christian (or Jewish, or Muslim) God. It would be hilariously ironic if Lewis were not using it that way.
IIRC, "God in the Dock" is the title of just one of the essays in the book, and many (most? all?) of the others aren't particularly about "accusations against God". The quotation in this thread, I think, comes from one of the ones that isn't.
Another month, another rationality quotes thread. The rules are: