You should find out what in particular led him to this path.
It is one thing to skip a mincha, or to eat a treif thing because of curiosity.
Here THere may be something bad that happened to him that should be discussed.
Also there can be psychological issues, for example, I myself, hate going to Shule, at times, because I hate the crowds, the whole social aspect. So sometimes I just don’t go.
Not saying this is a good mida, but
you see that reasons for actions are important.
Much luck to you.