From Jimmy Stephens:

Cultures depend on their notion of love vs hatred, prosecution vs forgiveness, justice vs grace, etc. There are several intersecting tensions here, but the main issue is how to deal with guilt.

All humans are guilty of something. None of us are perfect, so how can any of us (a) be in a position / claim the right to judge or (b) avoid execution? On the other hand, humans recognize some inherent rightness about “letting people off the hook,” different levels of responsibility, and different contexts where mercy is affordable. That’s unavoidable – just consider child-rearing.

So how do we think about and bring to bear these concepts in a successful way? The problem more severely stated is that anything less than judicial perfection will constitute injustice. On the other hand, pure justice for less-than-perfect agents leaves no room for mercy at all. None of us can escape failing perfection, and so no ordinary man, left to himself, escapes the same condemnation that removes any ground to adjudicate this question, theoretically or in practice: he will always be a hypocrite, and his hypocrisy, without any counter-evidence, will always undermine his judicial reliability.

So you can only have justice and mercy, love and hate, et al, reconciled by someone perfect.

(Blah blah blah – further conditions we’d want to establish are that you need to be Divine/God, and that you need to successfully satisfy the demands of justice, not merely know them.)