If you want to prove whether a person is truly as they claim to be; you can observe their every word and deed, every move and action.

If they only boast and brag, then they are a complete liar, lacking in true skills and knowledge, only possessing advanced deceit techniques, because such a scam can ensnare even the perpetrator, making it impossible to escape.

Of course, any knowledge must be applied to reality; you might as well try observing the posts of the masters around you by checking their homepage.

Will they choose to delete posts when faced with unexpected situations?

The results of practice are often the best truth.