Another related teaching:
One of the main teachings of the Buddha is the law of karma, the teaching that all the lives we have are not without cause, are not created by other beings, and are not by coincidence, but are all created by our own actions. All the positive things such as love, long life, good health, prosperity and so forth are also not given by anybody else. It is through our own positive actions in the past that today we enjoy all the good things. Similarly all the negative aspects, like short life, sickness, poverty, etc. and all the undesirable things are also not created by any outsider but by our own actions, the negative deeds we committed in the past.
If one really wishes to be free from suffering and to experience happiness, it is very important to work on the causes. Without working on the causes, one cannot expect to yield any results. Each and everything must have its own cause and a complete cause - things cannot appear without any cause. Things do not appear from nowhere, from the wrong cause, or from an incomplete cause. So the source of all the sufferings is the negative deeds.
Negative deeds basically means not knowing reality, not knowing the true nature of the mind. Instead of seeing the true nature of the mind, we cling to a self without any logical reason. All of us have a natural tendency to cling to a self because we are so used to it. It is a kind of habit we have formed since beginningless time.
However if we carefully examine and investigate, we cannot find the self. If there is a self, it has to be either body, mind or name. First, the name is empty by itself. Any name can be given to anybody. So the name is empty by itself.
Likewise the body. We say "my body". just like "my house, my car, my home, my country" and so forth, so the body and "I" are separate. If we examine every part of the body, we cannot find anywhere, anything called "I" or the self. It is just many things together that form what we cling to as the body or the self. If we investigate carefully from head to toe, we cannot find anywhere a thing called self. The body is not a self because the body has many parts, many different parts. People can still remain alive without certain parts of the body, so the body is not the self.
Likewise the mind. We think that the mind may be the self, but the mind is actually changing from moment to moment. All the time the mind is changing. And the past mind is already extinct, already gone. Something that is already gone cannot be called the self. And the future mind is yet to arise. Something that is yet to arise cannot be the self. And the present mind is changing all the time, every moment it is changing. The mind when we were a baby and the mind when we are an adult are very different. And these different minds do not occur at one time. It is all the time changing, all the time changing, every moment it is changing. Something that is constantly changing cannot be the self.
So now, apart from name, body or mind, there is no such thing called the self, but due to long habit, we all have a very strong tendency to cling to a self. Instead of seeing the true nature of the mind, we cling at a self without any logical reason. And as long as we have this, it is just like mistaking a colorful rope for a snake. Until we realize that it is not a snake but only a rope, we have fear and anxiety. As long as we cling to a self, we have suffering. Clinging to a self is the root of all the sufferings. Not knowing reality, not knowing the true nature of the mind, we cling to a self.
When you have a "self", naturally tere are "others" - the self and others. The "self and others" are dependent on the "self". Just like right and left, if there is right, there has got to be a left. Likewise, if there is a self, there are others. When you have a self and others, attachment then arises to one's own side, one's friends and relatives and so forth, and hatred arises towards "others" whom you disagree with, towards the people who have different views, different ideas. These three are main poisons that keep us in this net of illusions, samsara. Basically the ignorance of not knowing and clinging to a self, attachment or desire, and hatred - these three are the three main poisons. And from these three, arise other impurities, such as jealousy, pride and so forth. And when you have these, you create actions. And when you create actions, it is like planting a seed on a fertile ground that in due course will yield results. In this way we create karma constantly and are caught up in the realms of existence.
To be completely free from samsara, we need the wisdom that can cut the root of samsara, the wisdom that realizes selflessness. Such wisdom also depends on method. Without the accumulation of method, one cannot cause wisdom to arise. And without wisdom, one cannot have the right method. Just like needing two wings in order to fly in the sky, one needs both method and wisdom in order to attain enlightenment. The most important method, the most effective method, is based on loving-kindness, universal love and compassion, and from this arises the bodhicitta, or the enlightenment thought, which is the sincere wish to attain perfect enlightenment for the sake of all sentient beings. When you have this thought, then all the right and virtuous deeds are naturally acquired.
On the other side, you need wisdom, the wisdom that realizes the true nature of all phenomena, and particularly of the mind - because the root of samsara and nirvana, everything, is the mind. The Lord Buddha said: "One should not indulge in negative deeds, one should try to practice virtuous deeds, and one should tame the mind." This is the teaching of the Buddha. The fault lies in our wild mind, we are caught up in samsara or the cycle of existence. The purpose of all the eighty-four thousand teachings of the Buddha is to tame our mind. After all, everything is the mind - it is the mind which suffers, it is the mind which experiences happiness, it is the mind which is caught up in samsara and it is the mind that attains liberation or enlightenment. So when the true nature of the mind is realized, all other things, all other outer and inner things, are then naturally realized.
So what is the mind? If one tries to investigate where the mind is, one cannot find the mind anywhere. One cannot pinpoint any part of the body and say, "This is my mind." So it is not inside the body, not outside the body, and not in between the body. If something exists, it has to be of specific shape or colour but one cannot find it in any shape or any colour. So the nature of the mind is emptiness. But when we say that everything is emptiness and doesn't exist, it does not mean that it does not conventionally exist. After all, it is the mind which does all the wrong things, it is the mind which does all the right things, it is the mind which experiences suffering and so forth. Therefore there is a mind of course - we are not dead or unconscious, but are conscious living beings, and there is a stream of continuity of the consciousness, constantly. Just like the candle light that is burning, the clarity of the mind is constantly continuing. The characteristic of the mind is clarity. You cannot find it in any form or in any color or in any place, yet there is a clarity that is constantly continuing. This is the characteristic of the mind. And the two, the clarity and emptiness are inseparable, just like fire and the heat of fire are inseparable. The clarity and the emptiness cannot be separated. The inseparability of the two is the essence, the unfabricated essence of the mind.
In order to experience such a state, it is important first to go through the preliminary practices. Also, through preliminary practices one accumulates merit. It is best to meditate on insight wisdom. For that one needs to prepare the present mind, our ordinary mind that is constantly in streams of thoughts. Such a busy and agitated mind will not be a base for insight wisdom. So first we have to build a base with concentration, using the right method. Through concentration, one tries to bring the mind to a very stable state. And on such stable clarity and single-pointedness, one then meditates on insight wisdom and through this one realizes the true nature of the mind. But to realize such, one requires a tremendous amount of merit, and the most effective way of acquiring the merit is to cultivate bodhicitta.
So with the two together, method and wisdom, one can realize the true nature. And when one has realized the true nature, on the basis of that and increasing wisdom, eventually one will reach the full realization and will attain enlightenment.