When to love and when to let go

One of the comments I got on the "Unconditional Love" post contained the question: when do we love and when do we let go? Great question right. I really don't know what my answer is to this one. I look at this question from a stand point of your blood family (mother, father, sisters, brothers) and I really don't think there is a time that you completely let go of them. I think we loosen our grip but we never really let go. If you have a child who is 21, drinking and smoking, doing all kinds of wrong things and just seem like they can't get right; you tell them all the right things to do, you give them the best advice you can and then you let them do what they are going to do. But you never let go of your kids, you just loosen that grip a little. Now we may be sick and tired of them but we never really completely write them off. The rules seem to be completely different for our spouses and even friends. We have this long list of "stuff that I just ain't gonna put up with" that applies to the folks that we invite into our lives. It seems as though it's okay to put conditions on that love and because of those conditions it makes it easier to let go of those people. Really I think if you love someone you do everything in your power not to let go. If the other person doesn't want that love and they want to be let go, then I think you should give them what they want. No relationship can work with only one person carrying all the weight all the time. So I guess my big picture view on when to love and when to let go is: if you both are trying and want it to work; don't ever let go. Talk it through, get some counseling but don't let go. If one of you needs to be carried until you get your strength back then that unconditional love needs to kick in and you carry them. But if they are asking you to let go and that's what they truly want, then I guess that unconditional love should allow you to let them go if that's what's going to make them happy.