Is he Christian/religious/a believer? I have several books that tie in The Bible and spiritual healing in situations like his I would be willing to share, even send him from my library.

If not, there are many other places that can help him. Please understand this is a loss, he needs to be guided through the 5 stages of grief,

Denial
Anger
Bargaining
Depression and
Acceptance.

It's not just for when someone dies, it's for all part of life to which there is a loss.