Justify

Probably the person is going on to explain why they are confident that they will be a great lawyer.

AnonymousI will justify what I just said.

Normally one justifies an action one has already taken or justifies a course of action one expects to follow in the future. These are actions which require justification because they may be controversial. Simply being great at something is not the sort of thing that needs to be justified. It's not even an act

CalifJim Simply being great at something is not the sort of thing that needs to be justified. It's not even an action.

I'm pretty sure the thing that is to be justified is the statement or claim, not the state of being great. That is, an argument is going to be given as to why the statement is correct. Either that, or it is saying that the claim will be proved