Under normal circumstances, what we do now, either good or bad, definitely will affect future karmic results but not quite so imminently the manifestation of karma at present. However, exceptions are possible with special circumstances.

Reality is anything but sentimental. For eons, no one has been able to refute the existence of past and future life. This is the reality that everyone has to face. If one is not prepared when a calamity hits, no amount of worrying will help at that moment. Thus, practitioners must have the foresight to prepare for the unexpected and steadfastly take the path to liberation for themselves and others. While the body and the mind can still be exercised at will, one should seize every opportunity to practice, and practice diligently as an antidote to impermanence. Leave no chance for regrets later on.

People look at the same problem differently largely because of the state of their mind. Generally speaking, the mind of ordinary people is more fragile while that of the sages is strong. For instance, when the Buddha was about to enter parinirvana, he was surrounded by many arhats and practitioners. Although everyone knew the Buddha was dying and that they would lose not just a great but extraordinary teacher, all the arhats there were very calm. The exception was Ananda, who, having yet attained realization, was still an ordinary person. He stood crying by the side of the Buddha’s bed and could not contain his sorrow. The arhats were not disrespectful. Because they had already realized emptiness, they could pass beyond suffering.

- Quote from Are You Ready For Happiness? Don't Let the Paper Tiger Scare You Off, "How to Face Suffering"

Sometimes patients, after being diagnosed and given only one to three months to live, may continue living a healthy life three months later with the help of performing virtuous deeds such as liberating animals or undertaking a long life practice. When the patients go for check-up again, doctors find the symptoms all gone. This has happened in Tibet, China and other parts of the world. It is not hearsay or a fairytale but a fact, which somewhat validates the existence of causality.

Taming the mind is like taming an animal. When the mind is desolate and in despair, we should practice how to face suffering and transform adversity into courage and determination on the path to liberation; when it is immersed in pride and carried away by success, we should contemplate all things are impermanent and all defiled phenomena are suffering to overcome arrogance. We must avoid the two extreme states of mind and abide in the middle at all times.

- Quote from Are You Ready For Happiness? Don't Let the Paper Tiger Scare You Off, "Taming the Mind as in Taming the Elephant"

It is like on a summer day, or when the sun rises and it becomes warmer, a snowman or ice sculpture melts and disappears. Or sometimes in the midst of a blue sky, clouds appear in the shape of animals or solid structures but suddenly vanish without leaving a trace. Before realization is attained, the mind perceives all phenomena to be real. Once the nature of mind is realized, it will recognize the nature of either mind or consciousness is non-existent, like empty space. Suffering and happiness, which are attached to the mind, can also vanish suddenly without a trace like the clouds and ice. As in the saying, “To what do you attach hair if there is no skin?”

- Quote from Are You Ready For Happiness? Don't Let the Paper Tiger Scare You Off, "How to Face Happiness"

It is stated in the scriptures that if our motivation is found to be neutral, we should rather improve than eliminate it. The reason is that the quality of being “neutral” and “wholesome” are relatively closer to each other, whereas being “wholesome” and “unwholesome” are poles apart. So while the former can be improved, the latter must be given up. Ordinarily, before wesit down to practice or meditate, we should first examine the motivation carefully. If it was found to be neutral, we should improve it. Otherwise, none of what we do can lead us to enlightenment. The resulting virtuous karma caused by a neutral motivation may be able to bring some temporal rewards, but only very meager ones.

It is a simple and direct way to define Buddhism as wisdom and compassion. The broader and more profound connotation of Buddhism is the six paramitas.

- Quote from The Right View, "Buddhism—the Definition"

If you would like to know more about karma, you can read the fourth chapter of the Abhidharma-kosha-shastra, which clearly explains the workings of cause and effect.