Thinking yourself a “good person”, judging yourself, breaks the First Commandment. The Commandment that supersedes all others.
The worst sin.
No one is a “good person”; we are all fallen. For this reason, the Lord has promised that the “meek shall inherit the earth” and that “the first will be the last”. Only the meek are aware of humility. The “first”, proud and self-sufficient, have chosen to worship the material world and themselves.
Tragically, very few of them will find the humility required to save themselves.