A lot of religious people like to argue that atheists can’t be moral because they have no objective standard for morality.
The YouTuber at Counter Arguments does a wonderful job explaining why that argument doesn’t make any sense.

The response boils down to two points: Moral principles existed long before monotheism and parts of our brain can be stimulated to create empathy (suggesting it’s not God-given).
I would add that the people who claim God gives them morality often fail to recognize just how many people have done immoral things in their God’s name.