The INFP displays contrary qualities: gentle and caring, yet crusading, social and supportive, yet private and difficult to know. The INFP values most those who take the time, trouble and effort to really get to know them. Only those who are allowed through the INFP 'assault course' will get genuinely close. To others the INFP will seem like a gentle enigma.
My room-mate is an ENTP and I’m an INTJ. We both have a sarcastic and rather morbid sense of humour. However, nobody actually thinks that my room-mate might kill them, while I’ve gotten plenty of comments about how people fear I’m going to kill them in their sleep. When she uses sarcasm, she changes her facial expression and voice (subconsciously) to let people know that she’s joking (TiFe). I on the other hand do not (TeFi). All my jokes are told with a completely straight face.