"The only way of knowing a person is to love them without hope."
Walter Benjamin
20th century German philosopher
(I can hear you now; "How will he connect this one to business?")
If we substitute "trust" for "love" and "expectations" for "hope", are we not zeroing in on the goal we have for all new hires?
And note this is not to suggest that you don't do all possible to have reason to trust, as well as to establish expectations for performance, all prior to offering the job, but once you've done that . . .
The message is, do your best to find the right people and then step back and let them perform.