Will Small Penis Size Cause Problems In Sex Life?

hi this is for one of my friend , he is i think 27 -28 year old .he is very scared to get marry and reason for that what he is saying, his penis is small & i dnt knw ...he believes he cnt satisfy his future wife..i was trying to convince him in many ways bt nw he is going some kind of surgery or somthing .. will it be effected his future life???