Re: Identifying a Wali
Because their teacher, who is known to be a wali, gives them the status. A wali must go through rigorous training sometimes under numerous teachers, eventually they are given permission to give bayyah and call people to the tariqat. Most tareeqats will have a chain linking back to the Prophet Muhammad (pbuh), I can only tell you of ours, but the Prophet (pbuh) gave bayyah to Hazrat Abu Bakr Saddique amongst others who then passed on his knowledge to someone else, our chain goes through Mawlana Rumi and Shaykh Abdul Qadir Jillani and many many others, this process has continued to modern day. If you go to a proper tariqat they will show you the chain of teachers.
Also, like I said, as un-realistic as it sounds, you'll just know. You won't need to see the piece of paper which says who the wali's teacher is and it won't be something ambiguous, rather quite apparent. I guess to clarify I could tell you a story about my friends dad.
He was quite young, at university in England so although he was muslim he knew nothing of Islam, he was searching for 'something' but didn't actually know what he was looking for, then suddenly he began dreaming of these two old men calling him towards them. Obviously this guy was like (o.O) why are these old men calling me and he dreamt the same dream every night for months. One day the old men told him to look behind the fireplace.
He was obviously quite freaked out by it all but got a few friends together to pull the whole fireplace out, behind the 100's of years old fireplace were brand new books explaining Islam and our tariqat in a lot of detail, he checks the author out and goes to find him, lo and behold it's one of the old guys in his dream, and that was that. I've heard of hundreds of stories from very close people, so it's not chinese whispers, it's from people who have actually been through it all, I love stories like that <3
What I'm trying to get to is that as long as you intend to better yourself and intend to become closer to God, He'll send someone your way, you'll probably never need to look for him or verify him. We just all need to try our best at being good people :)
(I just read the 'divinely designated' part) I do think they're 'divinely designated' but they aren't Prophets, so they weren't given this status at birth, each one of us could become a wali, it's just so much hard work that a lot of us wouldn't bother. So although they are designated, it is not a monarchy or anything, anyone can become 'designated' so long as they work for it.