Do not judge according to appearance, but judge with righteous judgment. John 7:24
To judge according to appearance is to judge according to the flesh. Such judgment seems to achieve a place of being called righteous by making sure it establishes itself as being in the right and another as the legitimate offender. Fleshly judgment establishes itself upon technicalities and will use those technicalities to prove its own rightness. This is why it is impossible to let these so-called righteous fleshly judgments go. Instead, according to fleshly wisdom we learned that "time heals all wounds", not allowing ourselves to realize that older wounds get overshadowed and sometimes replaced by newer wounds making us suppose it just went away. We all know what it is to judge this way, it is all we knew before.
To judge according to Christ IS to judge righteously. It is the only possibility by which everything can be seen for what it is. Life is life, death is death. What else do we expect? What other rationale? Where else can we turn to see things as they are except in Christ. And in him we come to realize that all the technicalities in the world by which we might judge another do nothing more than to prove to us that there is no true right in any judgments we make according to appearance.
"Father, forgive them for they do not know what they do!" They THINK they know, we THOUGHT we knew ... and often even STILL THINK we know. But it is all a dead end street. In the end, according to righteous fleshly judgment, we would only find ourselves to be the same sinners we judge others to be.