Leviticus 19:17, Galatians 6:1 (the love of God/Christ includes criticizing people)

Thou shall not hate thy brother in thine heart: thou shall in any wise rebuke thy neighbour, and not allow sin upon him.
Leviticus 19:17

The excellent Thomas Manton has written two sermons on Leviticus 19:17
http://www.newblehome.co.uk/manton/vol19-lev.html
(if your web browser says there is a problem with the newble.co.uk website, ignore your web browser.   Copy this same URL, paste it in the long rectangle where you type the Web address, and re-try, and it will work)

I would add:
There is a fleshly definition of love, which is corrupt.
There is a Christian definition of love, which is true.

The fleshly definition of love (Psychology uses it) is to be comfortable and at ease in this world, enjoying food and entertainment and sins, and not getting criticized for sins or mistakes.

The Christ definition of love, is to deny yourself (including, what is described above), to follow all the commandments in the Word of God, and keep your heart and mind near to God.

This means that if other people sin, loving them requires you to criticize them, so that they know they are doing wrong, or are reminded that they do wrong, and have a chance at correcting themselves, and regain nearness to God.

That is love that is acceptable to God.

If you see other people sin, and do not correct them, then you actually hate them, because by sinning they are going toward hell and you don’t try to restore their heart/mind back to God.

However, in criticizing other people (when they sin), we have to keep in mind a few things:

• meekness:
  Brethren, if a man be overtaken in a fault, ye which are spiritual, restore such an one in the spirit of meekness; considering thyself, lest thou also be tempted.   Galatians 6:1This means, you have to be gentle in correcting another person, lest you get tempted.
  How would you get tempted?

  He who despises his neighbour, sins: but he who has mercy on the poor, happy is he.   Proverbs 14:21
  He who is void of wisdom despises his neighbour: but a man of understanding holds his peace.   Proverbs 11:12

  You would get tempted to despise the person who did wrong, because criticizing another person puts you in a position of teaching, which is some sort of power, and that would tempt you to rejoice not in Christ, but rejoice in being over other people, and even rejoice in other people having faults so as giving you an opportunity to speak about their faults, for the purpose of showing-off yourself.    If you do so, then you are not loving God, nor are you labouring for the good of the other person, you are trying to get yourself admired, rather than get God admired.

• whether the other person would listen, or would not:
  Speak not in the ears of a fool: for he will despise the wisdom of thy words.   Proverbs 23:9
  If a wise man contendeth with a foolish man, whether he rage or laugh, there is no rest.   Proverbs 29:9
  He that reproves a scorner gets to himself shame: and he who rebukes a wicked man gets himself a blot. Reprove not a scorner, lest he hate thee: rebuke a wise man, and he will love thee.   Proverbs 9:7-8
  A fool has no delight in understanding, but that his heart may discover itself.   Proverbs 18:2
  Go from the presence of a foolish man, when thou perceivest not in him the lips of knowledge.  Proverbs 14:7
  He that hideth hatred with lying lips, and he that uttereth a slander, is a fool.   Proverbs 10:18If the other person is of such a character as would not listen, then don’t waste time.   You have limited time on this earth, and there are many who don’t know Christ, but would gladly know Christ if told about Him.   Then there are those who really don’t want to know Christ.   Speak holiness to those who would listen.
• How old the other person is
  Rebuke not an elder suddenly, but intreat him as a father; and the younger men as brethren    I Timothy 5:1″rebuke not an elder suddenly” is the original text.    That means, you can rebuke an elder, as much as you would rebuke a neighbor to prevent him living in sin or making other people sin.  However, rebuke an elder in meekness.

Rebuking is part of Christian duties.
Half the Bible consists of criticisms.

Preach the word; be instant in season, out of season; reprove, rebuke, exhort with all longsuffering and doctrine.   II Timothy 4:2

All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness:   II Timothy 3:16