Getting back on topic --
We can debate all day about whether God said something or had any right to say something or whether we should believe that there is a God who did say something...
Brian said:
"If that's the case, it would suggest to me that one can sin without committing an act. While we're at it, isn't hate itself a sin, in Christian terms?"
That's what I recall -- for Christians who believe and practice, it's as much a sin to THINK about something you know is wrong, as it is to DO it.
Because either way, you're focussed on something God doesn't like -- acting and thinking are one and the same in the context.
I think the idea is to purify one's thoughts -- and steer away from thinking judgemental un-loving thoughts about others --
to try to "see God" in each person, and not be so focussed on their failings that we want to hate them.
(Yes Frank, I know and agree that many Christians do nothing BUT judge == welcome to why I am a Baha'i and not a Christian)
Or, to be so un-focussed on the spiritual world that we're overly concerned with the physical (sexual) world.
At the most fundamental level, it's about what IS our focus === Christians (and Muslims, amont others) have evolved those concepts into a massive set of rules to follow, mostly couched in terms of
"do not" sorts of things -- rather than having a primary focus on "do", they set their focus on "do not"