We've been debating via email. I realize I'll probably never change this person's beliefs, but if I can tackle arguments from one of the 'big boys' I can probably tackle any religious argument.
I've already picked up on mistakes I've made, things I wished I'd said differently, but the more I debate the better I'll get.
Here's the first part. I'm Chris, and Michael is the pastor.

Hi,
My name is Chris and I'm a friend of Josh, who attends your church. I've indicated to him I'd be interested in debating religion with you, and from what I've gathered, I think you're interested too.
You helped him out with a question I posed, which was 'Why aren't Christians killing gays now, as indicated in the laws of the Bible?'
It would make sense to continue from that point, although the possibility of debating other religious topics is high, and we may end up jumping to other things in the discussion. I welcome that, but it just makes sense to have a starting point.
So, to get the ball rolling and for clarity, I'll repost the help you gave Josh, followed by my reply.

'That's a very involved issue dealing with biblical penology. There are
some (radical theonomists) who do in fact advocate the death penalty by
the government (not individuals) for homosexual behavior. The passage
also calls for the death penalty for adultery, bestiality, and other
serious sexual abberations.

It's a question of how normative or standard should the penalties of
Levitcus 20 be for contemporary societies. I believe Muslim societies
still invoke capital punishment for homosexuality (and adultery). Some
theologians believe that the penalties are unique to ancient Israelite
society although the prohibitions are not.

The basic question is: Who decides whether or not homosexuality is
wrong and the penalties it deserves? God ro man? If Christian
governments are being inconsistent by not executing homosexuals then homosexuals
are benefitting. Governments are called by God to restrain sin and the
punishments they inflict are part of that.

The question could also be asked, "Why aren't Christian governments
giving the death penalty to murderers, adulterers, and those who lie with
animals?"'

I agree to all of that.
The bottom line though, is that contemporary Christian societies are going against God's laws by not killing people who do these things. It doesn't say in the bible that the punishments were only meant for biblical times, but the prohibitions remain in effect now. Adding to that point, many of the prohibitions are in fact ignored by modern day Christians for being ridiculous- not touching a woman on her period, not working on the sabbath, not wearing clothes made from two different kinds of material etc etc. Christians have picked which ones they wish to follow and which ones they wish to ignore, with no biblical reference for doing so.

I'm glad people aren't killed for these things, that's disgusting, but I feel the change in attitude has more to do with man's progression. Which is more valid? God's laws or man's morality? 'Who are we to question God?' is a line I hear often. If something is a sin, isn't it always a sin? If God says to deal with the sinners a certain way, and says nothing to change that, shouldn't the sinners be dealt with in that way, until God decides differently?

I'm not saying people should be killed, I'm showing how this is a clear example of the Bible's meaning being forced to change over time to fit in with modern society. The reason most Christians don't want to act so harshly is because it goes against their own morality, and yet other laws in the Bible are held up as shining examples of the way in which we must all live.