Needing an logical if formula

I am building a worksheet where on sheet one I have a list of several of my customers. On sheet two I want to show only customer's of a particular sales associate. I have a list of all of associate one's customers on sheet 3, titled John's Customers. I would like a formula that would search the list on sheet one, compare the customer ID Numbers on sheet 3, and if there is a match, populate the customer's name and contact information on sheet 2.