The real challenge for people who think that morals come from God is to list them. They can't. There is no list of morals.
Read the Old Testament and the list of "morals" you come up with are genocide, infanticide, misogyny, homophobia, and slavery, among others.
That's exactly right. I guess the typical Christian doesn't really read the Old Testament though. They probably don't really read the New Testament much either, but they have some talking points, and I think they believe these things are all from their God:
1. The Golden Rule (they'll cite the Matthew passage, but don't know that it existed in earlier forms, like the Silver Rule).
2. The two most important commandments you can keep are to love God and love your neighbor as yourself. Again, this is seen as very noble, but history would tell us it's just not original. There were things like the Code of Hammurabi from 1750 BC, or the Purvas of Jainism from the 9th Century BC, which heavily stressed interdependence and non-violence).
3. They see Jesus as a hero in the case of the woman that was to be stoned for adultery. How often do we hear that passage brought up? Of course, it's very interesting that it's a woman who is about to be killed there for adultery. It always seems to be the woman that is bearing the biggest punishments. Makes me think a little bit of Hester Prynne in the Scarlett Letter. David can cry out to God and receive forgiveness and love from God, even though he sets Uriah up for death in order to get Bathsheba. We don't really see that type of forgiveness for women if they cry out to God. We do here to an extent - but should this passage be so glorified? Isn't this just common decency?
4. Come on - he showed the ultimate morals in dying for our sins! But as we've all pointed out - why is that moral? Why is someone else dying for our mistakes a good thing? Shouldn't we all be responsible for our own actions, and also, shouldn't we learn from our mistakes? If you receive a blanket forgiveness for sinning - how is that good? How do you learn from your mistakes and grow as a person?
Those are the four biggest arguments I hear about morals coming from a God, and that's usually how I try to counter them. I also bring some strange things Jesus/God said in the New Testament that don't appear moral:
1. Servants that don't obey their masters will receive a severe beating (Luke 12:47)
2. The Parable of the Ten Minas (Ending in the craziness of slaughter Luke 19:27 - brought up in another thread)
3. He didn't come to bring peace but a sword/plus anyone who loves a family member more than Jesus isn't worthy of him (Matthew 10:33-40ish)
4. The turning over of the tables in the church market, and Jesus making a whip of chords and driving people out of the temple with it John 2:15-25ish - seems to contradict his thought on "live by the sword, die by the sword" cutting off of guards' ear by Peter).
5. Telling people that believe in him that they could handle deadly snakes, drink poison and not die, and heal people with their touch (Mark 16:16 - this starts pointing to him potentially being a lunatic in C.S. Lewis' "Liar, Lunatic or Lord" options.)
6. Killing of fig tree because it was out of season and didn't bear any fruit Mark 11:12-25.
7. In that same section of Mark, a promise that anything you ask for, it will be answered in prayer (also falls, potentially, under lunatic or liar options).
8. Matthew 15:26 - "It is not right to take the children's bread and toss it to their dogs." (refer to Canaanite woman as unworthy of his forgiveness, comparing her to a dog. Accepts her once she says "but even the dogs eat the crumbs that come from the master's table.")
9. Revelation 2:20-23. Because Jezebel refuses to repent of her sexual immorality, her children will be struck dead.
There are many other terrible passages in the New Testament, and I got tired after 8 (the 9th isn't attributable to Jesus). Do you all know others attributable to Jesus that are immoral? I guess there are the hell passages too (like the parable of the weeds). But I'm trying to compile as much as I can to counter the "well I don't believe in the Old Testament" argument.