The spiritual literature tells us that an attitude of non-attachment is a goal in spiritual development, or an endpoint on the road to enlightenment. What does this mean?
First we want to clarify what is meant by attachment before we consider its opposite. If we have our hopes set on a certain situation turning out a certain way, we say that we are attached to a particular outcome. We want to be sure it doesn't rain on our wedding day. We want to be sure the sports team we like wins the game. We fervently hope the new stock we just bought goes up. We want our favored political candidate to win the election. This is about our emotions. We want the outcome we want and if we allow ourselves to be attached to that outcome, we are saying we can't be happy unless it turns out the way we want.
Obviously, on issues over which we have little or no control, emotional attachment to a particular outcome only leaves us open to massive disappointment, and makes little sense. In the worst cases, it may lead a person to want their desired outcome so badly they will lie or do unethical things to try to control the situation. This is especially notable on the political scene today. But how can we find a way to avoid this very human tendency to want, or in the worst cases try to force, things to go our way?
Here I want to distinguish between some important terms. Let's suppose someone close to you, for example your brother, is having a very serious operation -- let's say coronary bypass surgery. You feel very sure it is important that your brother recover completely from the procedure, and return to being the same old brother you have always known. You go to visit, you worry. You feel nervous before the procedure and can hardly sit still during the hours it is going on. You hope, you pray that the surgery will be a success. This is a pretty normal way to react. But this is you having attachment to a successful outcome.
Now, let's consider a different response: Let's say you are already under a lot of stress from other issues in your life, and you cannot spare any energy at all to deal with your brother's surgery. You don't call, you don't visit. You don't pray for a good outcome. Instead you go about your everyday business, and pretend entirely that your brother's surgery is not happening. This is detachment -- it is NOT healthy.
In both scenarios above, the person is not dealing effectively with reality. The detached person is avoiding dealing with the situation altogether. She is avoiding showing her brother, or even admitting to herself, that she cares. But in not having made any psychological preparations to deal with a poor outcome, she is also setting herself up for major psychological pain if the surgery does not go well. Clearly, detachment is not a healthy way of handling reality.
But the attached person is doing only slightly better in dealing with reality. What if, despite all the prayers, and all the hand holding, the brother dies? What if the brother winds up incapacitated in some way? Does the attached person have any way of reframing the situation in her mind to avoid massive disappointment? We can see that attaching ourselves to a particular outcome is not the healthiest response either.
So how does a spiritually mature person avoid attachment in a healthy way? Well, the healthy alternative to attachment is not detachment, but acceptance. And the word acceptance allows us to distinguish between the unhealthy detachment in the scenario above, and the healthy attitude of non-attachment that spiritual masters recognize as a goal.
In acceptance, you acknowledge that you fervently hope your brother recovers, BUT you also recognize the many ways in which you do not have control over the outcome. You may still pray for his recovery, you may still look forward to having your same old brother back after the surgery. In short, you may STILL CARE.
But attachment differs from acceptance (or non-attachment) in that in the latter situation, you realize you do not have control over the outcome, and may not know all the factors. Perhaps your brother will have a very long struggle for his life and recover only after many months. It may be that he needed that time out from his regular life to reconsider some issues. Perhaps he will not recover at all and instead some of his organs will be donated to various people who still had a mission to fulfill in their life.
The point is, in acceptance we realize that our highest spiritual position is not to specify OUR desired outcome in any given situation. Even if your brother does not recover, even if he dies in surgery, if you can recognize that at some level, some good may have been served, then that is acceptance. This is perhaps a watered-down, but practical example of what the spiritual masters mean by the term non-attachment. Rather than rant and rail against the god that "chose" to let your brother die, in acceptance (or non-attachment) you can say "Thy will be done."