Measure of how nice/good you are - how you treat your "enemies"

Jesus teaches a very good lesson in the Sermon on the Mount and in Luke 6. It is not okay to judge how nice you are only by looking at your interactions with those who treat you well. Likewise, if you're nice to those who you expect to receive something from, you're not a great person, you're smart. The test is how you treat those you have nothing to gain from and those who actually treat you poorly.

Practically speaking, this probably means you can tell how nice you are by your willingness to speak with and get to know those who you will not benefit from. Surely there are many of these people in your life. Additionally, kindness to those who wish to argue with you or belittle you or who don't care about you is a real mark of goodness.

Essentially, we must be careful to not justify behavior by how other people act towards us. Their actions have nothing to do with how we should act. We are to act and not be acted upon. See 2 Nephi 2:26:

26 And the Messiah cometh in the fulness of time, that he may redeem the children of men from the fall. And because that they are redeemed from the fall they have become free forever, knowing good from evil; to act for themselves and not to be acted upon, save it be by the punishment of the law at the great and last day, according to the commandments which God hath given.

When a rock is thrown, it moves at the speed and in the direction of the person who threw it. It is something that is acted upon. People should not be acted upon, but should act, independent of the actions of those interacting with them. This is a major test of life.

Here's Jesus explanation of how we must act well in relation to all people (Luke 6):

31 And as ye would that men should do to you, do ye also to them likewise.

32 For if ye love them which love you, what thank have ye? for sinners also love those that love them.

33 And if ye do good to them which do good to you, what thank have ye? for sinners also do even the same.

34 And if ye lend to them of whom ye hope to receive, what thank have ye? for sinners also lend to sinners, to receive as much again.

35 But ^alove ye your enemies, and do good, and ^blend, hoping for nothing again; and your ^creward shall be great, and ye shall be the^dchildren of the Highest: for he is kind unto the ^eunthankful and tothe evil.

36 Be ye therefore ^amerciful, as your Father also is ^bmerciful.