The parsha of Kedoshim has the famous line: “Love your neighbor as your self”. What is often forgotten is what comes immediately before: -Do not hold a grudge. Interestingly, Yevamos 62 which is the next day after reading of Kedoshim this year, quotes the story of Rabbi Akiva’s students who died According to this page, they died because they lacked respect for each other. A footnote in the Arstscroll quotes a midrash explains that this manifested as an “inner flaw of stinginess of spirit?
It seems that a “grudge” or “stinginess of spirit” is very different than all other sins. It is not an action of hurt; it is not a statement of hurtfullness or offense. A grudge is an inner emotion deep in our consciousness. Grudges are a natural feeling that most humans encounter. A grudge or stinginess of spirit is part of the human condition or an understandable character flaw that all people can succomb to. In essence, it is part of the human condition. At best, we seek to control it.
The SD would like to weigh in. This is exactly where the standard of holiness comes into play. Holiness is NOT merely doing mitzvos or acts of chesed. Holiness is not simply complying with the Torah. Holiness is the transformation of self beyond normal human frailities and conditions. Holiness is doing these mitzos or acts of kindness in a state of true love and respect for others. Holiness is where you transform your soul to use all mitzvos as a springboard to improve your relationship with the neighbor-regardless of what the neighbor says or has or does.
Conquering our inner demons is what true holiness is. Love your neighbor really means, conquer your own demons, eradicate your negative feelings or petty emotions.