How far does love go? I think the problem comes here because we think the command to love has some promise attached to it, a promise about the response to the loving actions. I am not aware of any of those. Scripture doesn't say, "Love your neighbor so that . . . ." some result will come. It just says "Love your neighbor." Somewhere in Christian teaching we were given the sense that love for another will get an outcome such as a perfect relationship with them, no more conflict, no more snarkiness and hurt feelings, the other person's conversion, the other person's repentance from sin, the other person's breaking of a bad habit that just happens to make us crazy.
The commandment is absolute; no strings attached, so to speak, either before or after.
But love does not mean living someone's life for them. It means kindness, attention, prayer, lack of partiality (the point of James), sharing the Word, treating them as fully human, and helping when they are in true need, but not paying their bills, answering the phone and talking for hours every time they call, serving as their personal chauffeur or laundress, or doing things they are fully capable of doing so that they will see our Jesus-like love and then . . .well, do something wonderful in response.
It also doesn't mean agreeing with them or taking abuse or not holding them accountable. In short, we have gotten a really sick view of love, which then only piles on the guilt when we fall short of being able to do all this for someone.
Which brings us to the second question, one I really liked. How do we know what sin is? One member of the class works in a phone ministry and a woman called and asked why it was a sin not to go to church, since it wasn't in the Ten Commandments. My answer was that first the person didn't understand the difference between what the Old Testament means for Christians and what the New Testament teaches. The law brings us to knowledge of sin so that we see our need for Christ; the New Testament teaches us a new law, of love and liberty, that sometimes looks like the Old Testament law but really is of a different quality (not worse or better, but different purpose and source). Hebrews 10:24 and 25 commands physical assembly with other Christians for clearcut purposes.
Furthermore, if one asks for God to show sin in one's life, it will become clear, most of them being rooted in the heart. And if someone knows to do good and does it not, for him it is sin (James). But society, culture, and the media will also try to make you feel guilty about any number of things that have absolutely no connection to the holiness of God. My house is currently rather dirty--dusty and dirty floors, primarily. Does God care? I think God cares more that I am exhausted and having trouble holding my head up right now. He is more concerned that I spend some time with my husband, who needs encouragement. This is no excuse for the housework--it will get done, but an unmopped floor is not a sin. If we confuse sin with violating some social norms we have lessened sin as well as elevated unimportant matters.
Control is the key word here. Control is an illusion, but it is also one of our biggest problems. It is the opposite of "radical dependence," which we are commanded. A lot of my conflicts come from the mistaken idea that I have control over a situation, I should have control over it, and my control will be rewarded. On Thursday I am having a nuclear stress test because of my fatigue and shortness of breath, something I can't control. There is precious little we control, yet we cling to that illusion and then let ourselves be made guilty for not meeting an impossible standard.