An absolute moral standard — there just has to be one. Two weeks ago, I wrote about how we choose to allow others to treat us. It grieves my heart that humans justify their actions when they harm another.
I am addressing family dynamics at this time. Using foul language, physically or psychologically abusing a spouse or child, and then justifying it, is wrong in the eyes of God. If there are patterns in yours or another's life, using excuses like "stress" or "they provoked me" do not dissolve the sin in the eyes of God.
As children, we develop patterns of attachment with our caregivers. When these patterns or our upbringing have been dysfunctional, or allowed dysfunctional behavior, we can grow into adults who treat others in a poor manner and then justify it. In circumstances like these, as Christians, good Christian therapy can a valuable resource to work out some of those dynamics.