To want unwaveringly the welfare of another both in the head and heart is the best help one can give.
[SABCL, 23:831]
I have already told you several times that if one thinks clearly and powerfully, one makes a mental formation, and that every mental formation is an entity independent of its fashioner, having its own life and tending to realise itself in the mental world—I don’t mean that you see your formation with your physical eyes, but it exists in the mental world, it has its own particular independent existence.   If you have made a formation with a definite aim, its whole life will tend to the realisation of this aim. Therefore, if you want to help someone at a distance, you have only to formulate very clearly, very precisely and strongly the kind of help you want to give and the result you wish to obtain. That will have its effect. I cannot say that it will be all-powerful, for the mental world is full of innumerable formations of this kind and naturally they clash and contradict one another; hence the strongest and the most persistent will have the best of it.
Now, what is it that gives strength and persistence to mental formations?—It is emotion and will. If you know how to add to your mental formation an emotion, affection, tenderness, love, and an intensity of will, a dynamism, it will have a much greater chance of success. That is the first method. It is within the scope of all those who know how to think, and even more of those who know how to love. But as I said, the power is limited and there is great competition in that world.
Therefore, even if one has no knowledge at all but has trust in the divine Grace, if one has the faith that there is something in the world like the divine Grace, and that this something can answer a prayer, an aspiration, an invocation, then, after making one’s mental formation, if one offers it to the Grace and puts one’s trust in it, asks it to intervene and has the faith that it will intervene, then indeed one has a chance of success.
Try, and you will surely see the result.
[CWM2, 8:253-54]
Note that this power of formation has a great advantage, if one knows how to use it. You can make good formations and if you make them properly, they will act in the same way as the others. You can do a lot of good to people just by sitting quietly in your room, perhaps even more good than by undergoing a lot of trouble externally. If you know how to think correctly, with force and intelligence and kindness, if you love someone and wish him well very sincerely, deeply, with all your heart, that does him much good, much more certainly than you think. I have said this often; for example, to those who are here, who learn that someone in their family is very
ill and feel that childish impulse of wanting to rush immediately to the spot to attend to the sick person. I tell you, unless it is an exceptional case and there is nobody to attend on the sick person (and at times even in such a case), if you know how to keep the right attitude and concentrate with affection and good will upon the sick person, if you know how to pray for him and make helpful formations, you will do him much more good than if you go to nurse him, feed him, help him wash himself, indeed all that everybody can do. Anybody can nurse a person. But not everybody can make good formations and send out forces that act for healing.
[CWM2, 5:132-33]

Change yourself first

If through an effort of inner consciousness and knowledge, you can truly overcome in yourself a desire, that is to say, dissolve and abolish it, and if through inner goodwill, through consciousness, light, knowledge, you are able to dissolve the desire, you will be, first of all in yourself personally, a hundred times happier than if you had satisfied this desire, and then it will have a marvellous effect. It will have a repercussion in the world of which you have no idea. It will spread forth. For the vibrations you have created will continue to spread. These things grow larger like the snowball. The victory you win in your character, however small it be, is one which can be gained in the whole world…. all things which are done outwardly without changing the inner nature—hospitals, schools, etc.—are done through vanity, for the feeling of being great, whilst these small unnoticed things overcome in oneself gain an infinitely greater victory, though the effects are hidden. Every movement in you which is false and opposed to the truth is a negation of the divine life. Your small efforts have considerable results which you don’t even have the satisfaction of knowing, but which are true and have precisely an impersonal and general effect.
If you really want to do something good, the best thing you can do is to win your small victories in all sincerity, one after another, and thus you will do for the world the maximum you are able to. 
 [CWM2, 05:19-20]

Will our victory act for the whole world?

It will not change the whole world. For your victory is too small for the whole world. Millions of such victories are needed. It is a very small victory if compared with the whole. But it gets mingled with other things…. It could be said that it is like bringing into the world the capacity of doing a thing. But for this to act effectively, at times centuries are necessary; it is a question of proportion. You can try it out (and it is much more difficult) even with those around you. You must be absolutely sincere, not do it with the idea of getting a result, but because you want to gain a victory. If you gain it, it will necessarily have an effect on those around you. But if a bargaining element is mixed up in it, if you do this thing because you want to get that other: “I want to overcome my defects, but that person must also overcome his”, then that doesn’t work. It is a merchant’s attitude: “I give this, but I shall take that.” That spoils everything. There is neither sincerity nor purity. It is bargaining.
Nothing must be mixed with your sincerity, your aspiration, your motive. You do things for love of the Divine, for truth, for perfection, without any other motive, any other idea. And that brings results.”
[CWM2, 05:20]

 Is it very important to know oneself?

Very important, of capital importance! Besides, that’s the field of work given to each one. It is this one must understand, that each one-this totality of substance constituting your inner and outer body, the totality of substance with which your being is built from the outermost to the inmost-is a field of work; it is as though one had gathered together carefully, accumulated a certain number of vibrations and put them at your disposal for you to work upon them fully. It is like a field of action constantly at your disposal: night and day, awake or asleep, all the time-nobody can take it away from you, it is wonderful! You may refuse to use it (as most people do), but it is a mass to be transformed that is there in your hands, fully at your disposal, given to you so that you may learn to work upon it. So, the most important thing is to begin by doing that.You can do nothing for others unless you are able to do it for yourself. You can never give a good advice to anyone unless you are able to give it to yourself first, and to follow it. And if you see a difficulty somewhere, the best way of changing this difficulty is to change it in yourself first. If you see a defect in anyone, you may be sure it is in you, and you begin to change it in yourself. And when you will have changed it in yourself, you will be strong enough to change it in others. And this is a wonderful thing, people don’t realise what an infinite grace it is that this universe is arranged in such a way that there is a collection of substance, from the most material to the highest spiritual, all that gathered together into what is called a small individual, but at the disposal of a central Will. And that is yours, your field of work, nobody can take it away from you, it is your own property. And to the extent you can work upon it, you will be able to have an action upon the world. But only to that extent. One must do more for oneself, besides, than one does for others.
I don’t think, truly, sincerely I don’t think that it is possible to help anyone unless one has already helped oneself first. If you are unconscious, how do you expect to bring consciousness into others! This seems to me an insoluble problem. That is what people usually do, but that’s no reason for approving it. This is exactly why, I believe, things go so wrong. It is like those who seeing others quarrelling rush forward and begin shouting louder than they to tell them, “Keep quiet!”
[CWM2, 05:302-03]

In dealing with others what is the best attitude?  Should it be one of intervention or of non-interference?  Which one is better?

…to intervene you must be sure that you are right; you must be sure that your vision of things is superior, preferable or truer than the vision of the other person or people. Otherwise it is always wiser not to intervene—people intervene without rhyme or reason, simply because they are in the habit of giving their opinion to others.
Even when you have the vision of the true thing, it is very rarely wise to intervene. It only becomes indispensable when someone wants to do something which will necessarily lead to a catastrophe. Even then, intervention is not always very effective.

When is Intervention Justified?

In fact, intervention is justified only when you are absolutely sure that you have the vision of truth. Not only that, but also a clear vision of the consequences. To intervene in someone else’s actions, one must be a prophet. And a prophet with total goodness and compassion. One must even have the vision of the consequences that the intervention will have in the destiny of the other person. People are always giving each other advice: “Do this, don’t do that.” I see it: they have no idea how much confusion they create, how they increase confusion and disorder. And sometimes they impair the normal development of the individual.
I consider that opinions are always dangerous and most often absolutely worthless.
You should not meddle with other people’s affairs, unless first of all you are infinitely wiser than they are—of course, one always thinks that one is wiser!—but I mean in an objective way and not according to your own opinion; unless you see further and better and are yourself above all passions, desires and blind reactions. You must be above all these things yourself to have the right to intervene in someone else’s life—even when he asks you to do so. And when he does not, it is simply meddling with something which is not your business.
[CWM2, 10:235-36]

The best way of helping others

To help others is the best way of helping oneself. For, if you are sincere, you will soon discover that all their difficulties and all their failures are the sure signs of the same corresponding deficiency in you. Indeed, they prove that something in you is not perfect enough to be all-powerful.
                                                                                            *
We find in others what is in us. If we always find mud around us, it proves that there is mud somewhere in us.
[CWM2, 14:275]
The best way of helping others is to transform oneself. Be perfect and you will be in a position to bring perfection to the world.
[CWM2, 14:276]