Free will

I saw a comment section filled with Christians saying that we don’t have free will which is a very atheistic view. If there is No God we’re just primordial slime evolved to a higher order only functioning off of what our biological chemicals/ instincts tell us to. Which would ultimately mean there is no free will in that case. There would be no “soul” or a “you”. So I’m confused on how believers come to that conclusion. Any thoughts?