I've only ever known female INFJs, but I love them.
I have a lot of respect for INFJs because they seem to be able to manifest qualities that I feel, but can't show. They are very caring and it's amazing to watch them at work in that capacity. While I pillory myself because I just can't see how it's possible to end a person's sadness, an INFJ is there actually making an attempt - and doing a good job. I love being around them because they don't judge me for my flights of fancy. I also think I serve to strengthen their self-confidence by telling them to forget everyone else in the world and just do what you want as long as you don't hurt anyone. I've never worked out why they feel so insecure because I've never met an INFJ that wasn't a lovely person.
I am fiercely protective of INFJs because I recognise that they are almost like the INFP's hands in the world. They do the things I wish I could but can't because it's too emotionally tortuous: if I see a child that's upset, I get upset for them; an INFJ will actually go and make things better. In this sense, I feel like I will take the slings and arrows on their behalf so they don't ever have to feel bad - they've got too many gifts that might be wasted if they feel sad. I'd rather that I feel sad for them and they feel happy and caring!
In a way, I think we both look at each other and see the things we lack in ourselves. As I've said, I see the "pastoral care" present in an INFJ that I wish I could offer but can't. Likewise, I think they see in INFPs a strength of character which allows us to disregard everyone else and follow our own whims.
It's a great partnership, and I wish I knew more INFJs.