To clear up a point from my post on, "Hate the sin, love the sinner," my position is this:
We ought to hate sin. We ought to love sinners. We ought not tell each other and ourselves, "Hate the sin, love the sinner." It is as a maxim or a rule that the statement is bunk.
A rule of conduct must be sound and correct on its own, without additional context. "Hate the sin, love the sinner" fails to do this, on both the "hate/love" and the "sin/sinner" parallels.
Hate and love are not parallel in Christian thought. The second greatest commandment is not, "Hate what is opposed to the LORD your God with all your heart, soul, mind, and strength." Christian hatred must be situated within the larger context of Christian charity, and that maxim doesn't do that.
True, the lack of parallel between "sin" and "sinner" --
As an aside, what are the contraries of "sin" and "sinner"? English doesn't have a word meaning "a morally good act," and the customary "saints and sinners" pairing is actually a class ("sinners") and a sub-class ("saints"), not two mutually exclusive classes.
-- can be taken as an attempt to provide the context ("love the sinner") for the root maxim ("hate the sin"). I don't think that's a very convincing take on it, but even if that were the intent, it wouldn't rescue the saying.
A maxim is a shortcut, a way of reducing a problem (or at least one part of a larger problem) to one that has already been solved. So "you may not do evil that good may result" shaves away all intrinsically evil means to the end you seek. Show that a means under consideration is intrinsically evil, and you're done with considering it.
"Hate the sin, love the sinner" doesn't seem to work that way. As applied by fallen human beings, it tends to devolve to either hating the sinner or loving the sin.
St. Augustine is generally held to be the inspiration for the formula. And in fact I'd say, "Observe due love for the persons and hatred of the sins," which is pretty much what he wrote, is a great improvement over the more common version Gandhi popularized. Not just because it starts with love rather than hate, but because it doesn't present them as contraries. They're both things that are due, and the words themselves give no suggestion that the listener is expected to be more inclined toward failing in one direction than the other.