There are may ways to support people with bipolar. One of the key things is to understand the relationship you are in with them. As well as your proximity.
There can be two different outcomes from bipolar support- one which produces a recovery, and one which creates a life long dependence and disability. You have to decide what sort of an outcome you want to create. Nobody who supports another can decide on any outcome actually; it is all dependent upon the person who is suffering. Are they going to accept it for the rest of their life that they are going to be ‘mentally ill’ and therefore dysfunctional or are they going to believe that ‘ok, this is how I am and not let me get on with the rest of the business.‘?
There will be days when your loved one will be extremely functional and capable of doing everything, but there may be spells when the mood swings to another extreme and debilitates them. This is the time to support them and encourage them to do whatever little they can, trying to remain useful, even if not optimally so. Pushing them hard is never a solution, neither are your inspiring words. People who keep doing even a little everyday will eventually turn things around in their favour. Those who are protected by families in the belief that they are ill will become more and more ill and debilitated over time.
Your support does not mean that you have to try leading the person towards any outcome- they will produce their own outcomes. Just try not to guide them too much, except during phases when they lose self confidence, hope and courage, when anxiety overcomes them and makes the head go into a spin and fog engulfs the soul. Only on those days you need to offer courage and gentle support. Rest they will manage and accomplish everything they want in life-including professional competencies, relationships and you name it.
Never think anyone who has a mental illness label is a stupid person and they need your guidance or direction at any time, most of the time. Yes they may need it once in awhile- the courage that they have lost momentarily must come from the words of another. So kindly do not offer it, but sense the need for it and only then support them.