If you think she only did it for the money, you haven't even 'scratched the surface'. [=there are many other factors, reasons, etc., involved]
Despite the 'surface' differences between the two candidates, they are very similar in most ways.
The tension between them is beginning to 'rise to the surface'. [=it is becoming easy to see]
(..) to say something. I have been listening very carefully and... it seems to me that this man has some very good points to make. From what was presented at the trial, the boy looks guilty, on the surface. - But maybe if we go deeper... - Come on, will ya? There is a question I would like to ask. (..)1957 12 Angry Men