This Shabbos I heard an interesting dvar Torah from my rabbi.
In parshas Veyeira, Avraham did four things (amongst many others): he showed hospitality to strangers, he argued with G-d regarding destruction of the two cities, he kicked out his concubine and Sara's servant Hagar and her son Yishmoel, and finally, he participated in akeidas Yitzchok — an almost-sacrifice of his son.
This sequence of events is interesting in that it tests the main trait of Avraham's character — his kindness. Now, the first act, showing hospitality to guests, was not really much of a test. It was a natural thing for Avraham, who was a man of kindness (to the point that it says in one Midrash that during Avraham's lifetime Hashem's attribute of Chesed, kindness, complained that it's been replaced by Avraham). The second act was more difficult, since it involved arguing with G-d, but it was also quite a natural thing to do: Avraham had to argue in favor of people who were going to be destroyed, trying to find even one righteous person in their midst.
With the third act, however, we are already finding Avraham doing that which is not natural to him. And I am not only talking about arguing with his wife (it's not clear what took more guts: arguing with her or with G-d). Avraham had to send to possible death his son and the concubine who gave him birth. And sure, Sara's reasons were perfectly valid: she was looking at the bigger picture of transmitting her's and Avraham's message and purpose in life and creating a Jewish nation. When it became obvious that Hagar and her sone were not the right medium for it (and in fact would be counterproductive to this effort), Sara had to "let them go". Nevertheless, it took pursuasion from G-d for Avraham to do that which was completely against his essence: to apply gevurah, strictness.
The fourth act, however, was a paradigm shift in difficulty, and it was the one that made Avraham into a Jew. Avraham had to go against his character completely, against everything that felt right to him, for no obvious reason except G-d's word. One lesson in that was that G-d's word was enough. A Jew cannot determine himself what his service to G-d is going to look like; he has to listen to what G-d demands. The other lesson was that a Jew may have to go completely against his nature and change his nature in order to serve G-d. The third lesson, which was the essence of my rabbi's dvar Torah, is that sometimes you have to do something that feels wrong. If you know objectively, rationally, that it is right, but subjectively, intuitively, it feels wrong — well, you have to go with the truth. Truth is not sentimental. Especially when we are talking about eternal truth, about connection to Hashem. (And presumably, in a Jew's life, everything is, one way or another, about connection to Hashem.)
For myself, there is another lesson yet. Sometimes when dealing with those who are dear to us, with our friends, with our relatives, with our parents, with our loved ones, with G-d Himself, we tend to do what feels right to us. What we are accustomed to, in a way that makes sense to us. Sometimes, however, it is not the right thing to do. Sometimes (or maybe always), the right thing to do is to find out what makes sense to and what is right for the other person — and do it that way, even if makes no sense to you, even if it "feels" wrong, even if you would not want this done this way to you. Because, if you're doing something for the other person, you have to do it for that person, not for you.
So, don't say "this is the best I can do". Because what you're really saying is: "This is what I do; this is my modus operandi, and here is my best effort at it". You have to stop doing what "you do" and start doing what the other person needs. If you truly love and care about the person.
Of course, as our Sages say, the biggest distance is between a person's mind and heart, and sometimes one's neck is quite narrow. Sometimes it takes time between knowing what is right and starting to do it. But even knowing what is right is already a good start.