Come on, folks. The OP is trying to talk to someone who doesn’t believe in God, or who is desperate not to believe in God. Jesus is a good argument for a believer, but not for an unbeliever.
Keep it simple. Talk about things like, “If we are all just chemical processes, why are you bothering to talk or have opinions?” Or, “So I would just be doing something natural and harmless if I kill you and end your chemical processes? Can I have your bank account first?”
Well, okay, that last is a little aggressive… maybe don’t use that, unless you are talking to an unbeliever with a sense of humor!
Anyway, there are three kinds of people who usually have this line of unbelief.
A young kid who likes the argument as “Whoooooa, that is such a deep thought!”
Somebody feeling guilty about something bad they did, or want to do. (Because if it’s a chemical process to mess with your best friend’s girlfriend, it’s totally not your fault, right?)
Somebody feeling suicidal, or guilty and suicidal. (So yeah, don’t use the killing argument on this guy, even if he has a sense of humor.)