Quote Originally Posted by TheEmeraldCanopy
Is it a cardinal sin to just outright ask an INFJ if the reason they are avoiding you is because they need space?
Pretty much (in my opinion). If you outright ask an NFJ if they need space, they're likely to not want to hurt your feelings by telling you they do need space, so they'll come up with some excuse. If you beat around the bush, and appeal to their emotions, they might be more likely to tell you the truth.

For example, I'd most likely worry that I'm hurting your feelings so I'd lie if you said this:
"You're avoiding me. Do you just need space or something?"
And be more likely to be honest if you said this:
"I've been noticing that you haven't been trying to talk to me for the past [insert time here]. I feel like you're avoiding me and I'm worried about you. Do you just need some time away from me? Please answer; I care about your feelings."