Why people ask it
Because they have read or heard passages that are genuinely disturbing, and the usual answers feel like evasion.
Short answer
Some of these passages are genuinely hard and should not be softened. Interpretation requires attention to genre, historical context, and the difference between narrative describing events and text prescribing behavior.
Deeper answer
The worst possible move here is to sound comfortable. Some of these texts are difficult for thoughtful Christians too, and admitting that is the entry price for being taken seriously.
Several distinctions do real work. Much of the difficult material is narrative — the text reporting what happened, including things it does not endorse. Ancient Near Eastern conquest language used conventional hyperbole that modern readers take literally. And law codes given to one nation in one period are not presented as universal ethics.
Those tools resolve a meaningful portion of the difficulty and not all of it. The honest position names which cases are addressed and which remain open, rather than claiming a clean sweep. A short list of hard cases held openly is more credible than a long list explained away.
Common mistake
Rushing to defend every passage. Some require sustained study, and "I need to look at that one more carefully" is a legitimate answer.
Conversation-ready response
""Some of those passages are hard for me too, and I am not going to pretend otherwise. Which one are you thinking of? I would rather work through a specific text than talk about it in general.""
Source notes coming soon.