Mostly, faith is learnt through hard work. The greatest lessons in life are learnt through our pain. When life is good we don't really need faith but when life is difficult, it's a different story.
Difficulties cause us to question life and it's meaning and this is when we grow.
Life can involve looking back and regretting certain decisions or wishing for a different outcome. There's much, though, no matter what, that can be learnt in the process.
There are choices in the process. We can still be fruitful even in difficult situations. (James 1:12)