So what happens when two people in the same or similar situation define the same action, one defines it as good, the other as evil? It’s pretty easy to construct a situation where each person feels morally justified in killing the other.
That doesn’t seem like a very useful morality.
While it may sound similar it’s meaningfully different. Jesus’ statement asserts that good is an attritibute that can be had by some being, just not you or me. I am asserting that good is not something anyone can be. There’s no deity involved here.
That not only am I not a good person, it’s mostly impossible for a person to be truly good. Even knowing what good is, in its entirety, is nigh impossible. The best that can be done isn’t necessarily within my energy and/or skill.
There are wrongs that cannot meaningfully be righted.
Doing a little good some of the time is the most I can ever aspire to.
You could get put in jail for no reason and risk being sent to a concentration camp.