As such, the Harry Potter (HP) books can illustrate and clarify some of the most important questions of value that confront us in the world today.
One such is that the single most important choice a person makes is which side to take: the side of Good or that of evil - and there are only two sides.
In the HP books, Voldemort is a picture of Satan, and his side includes both a cadre of Death Eaters (analogous to demons), and a great mass of people who just go-along-with the agenda of evil for various motives - serving its overall goals, and passively absorbing and adopting its core beliefs and motivations.
In life, as in Harry Potter, there is no value-neutral position, and sooner-or-later it seems that everybody (even the non-human magical 'creatures such as House Elves, Centaurs, Goblins and Giants) is compelled to pick his side, and choose one way or the other.
And also as in life; in the fictional world of HP - some nice people chose the side of evil; while (more or less) many of those on the side of Good are (more or less) nasty people
This aspect of Harry Potter has particular value in these times, since our situation seems to be that most of the nice (decent, sensible, hard-working, intelligent, kind..) people are on the side of evil; while many of those on the side of Good are more-or-less nasty.
Perhaps the major nasty person on the side of Good is Severus Snape; who is represented throughout as a thoroughly nasty man - yet one who by his great courage and genuine love (for Lily Potter, Harry's mother) has heroically chosen the side of Good.
Another less obvious example is Dumbledore; who emerges as a greatly flawed character, with a strong tendency towards deception and manipulation and who struggles with a temptation for power and an almost paralyzing sense of guilt for his past affiliation to evil and its consequences; yet who is more solidly on the side of Good, and working-for Good, than almost anyone.
An even less obvious example are the Weasley Twins - Fred and George. These share a tendency to callous cruelty, indeed sadism, which is a serious character flaw. In general they are hedonistic and manipulative without regard for the consequences for others, although because they are charming and 'cool' they are generally well-liked. But Fred and George are always staunchly and courageously on the side of Good - because they are sustained by an indomitable fraternal and familial love, which is their bottom line.
And while the Death Eaters are almost always very nasty people, there are several on the side of evil who would be regarded as 'good guys' in terms of everyday social behaviour.
For instance, Cornelius Fudge, the Minister of Magic (in the earlier books) is a kindly and avuncular character, and his faults would seem to be mostly minor: cowardice and untruthfulness, unacknowledged incompetence, and wilful blindness to the reality of evil emergent. Yet these faults are unrepented such that that he ends-up working for the triumph of Voldemort and against those who oppose him; this despite believing himself to be motivated towards Good. Fudge is a type seen frequently these days - heading-up major social institutions of all kinds (including leaders of the self-described Christian churches).
The later Minister of Magic - Rufus Scrimgeour - also ends-up on the wrong side despite his admirable courage and staunch opposition to the Death Eaters; because he subscribes to various Big Lies, and becomes corrupted by the doctrine that the end justifies the means. He wants Harry to participate in various official lies, tries to blackmail and bribe him; and attempts to make Harry subordinate his 'chosen one' mission to the current 'needs' of propaganda and the magical bureaucracy. He also dishonestly imprisons (with torment) the naïve and innocent Stan Shunpike, on the pretense that SS is a Death Eater, because Scrimgeour believes this will help the cause.
Ludo Bagman - the Head of the Department of Magical Games and Sports - is another 'type' seen among the nominal leaders used by the Global Establishment nowadays (e.g. Boris Johnson). A charming, popular man - for whose incompetence and stupidity people are usually prepared to make excuses because they find him likeable. "Ludo" emerges as a self-interested gambling addict and defrauder; one who bought his position by providing secret insider information about the Ministry to a Death Eater; and who abuses his position for his own pleasure and profit. Bagman (the name implies a criminal go-between) overall, in many ways, aids the ascent of Voldemort.
JK Rowling is clear that the determinant of a person's status of Good or evil is which side they take; and also that the two main virtues that most matter in this choice are love and courage.
Love is, of course, the core Christian virtue which 'drives' all that is Good - while courage is necessary for that virtue to remain dominant, and to resist the insidious, pervasive and powerful forces of corruption when evil becomes dominant - when "The Ministry has fallen".
Lack of courage - cowardice, represents a lack of faith in the cause of Good, and concern with the expediencies of this world rather than fundamental values; so that fear unrepented and unopposed is the root cause of a great deal of corruption.
Self-sacrifice is required of all the Good characters at some point in the series; and this is not possible without the right motivation of love, and the key virtue of courage in that cause.
Harry himself is naturally the greatest moral exemplar. A very flawed hero; throughout the books he comes to a clarity and conviction of what matters most - what must not be given-up; and eventually he makes the ultimate sacrifice by which the world is saved from evil.