Do "justification of" or "justification for" mean different things? Is one more appropriate than the other?
If you are describing the action being justified, say "justification for". If you are identifying the person offering the justification or being justified, say "justification of".
For example, "What was Bob's justification for arriving late?" vs "We listened to Bob's justification of himself."
The same is true when the word is used in a theological context. "We receive justification for our sins through the atoning work of Christ" vs "The justification of the sinner is received ..."
Or if you're thinking of "justification" in the sense of the placement of text on a line, you should always use "of". "The justification of the customer name on the form is determined by ..."
There is a slight difference.
But if you say the example 1 "for", something feels a bit awkward.
However, if you use "for" in example 2 you don't really feel a difference.
Hope I haven't confused you.
My point is, use whatever (of or for) without hesitation.