A close friend of mine is r"l slipping down very bad. Right now he is at the stage where r"l he doesn't believe in "Torah min hashamyim", "am hanivchar", etc. can anyone recommend any solid good books on these topics which I can send him to read?
Wasn't sure where to post this. Couldn't find anything on this topic. If there is a already a thread on this topic please direct me
I don't know that sending your friend "solid good books on these topics " will help him.
Your friend needs personal guidance and help. First and foremost he probably needs someone that will listen to him. One probably needs to get down to what has triggered this, before being able to help.
There are people out there who specialize in this. Knowing the age of your friend, some background, and what he does now, might help in pointing at at the right direction for help. Don't reveal any personal information publicly, but if you give general information, maybe you'll get some recommendations.