The three existences are impermanent, like autumn clouds;
the birth and death of beings are like a dance performance;
the course of a being's life is like a flash of lightning;
it goes fast, like a steep mountain waterfall.

- Lalitavistarasūtra

"Even if we have completed our quota of years and months on retreat and managed to recite millions and millions of mantras, unless attachment, hostility, and ignorance have decreased in our minds, that Dharma I consider as just pointless.”

- Patrul Rinpoche

"Every day recollect the hells, which are fiercely hot and bitterly cold. Remember too the hungry ghosts, emaciated by hunger and thirst.

Observe the animals and recollect their numerous sufferings of confusion. Relinquish their causes, engage in causes of happiness.

Once you have gained what is hard to gain, a human body in this world, endeavor to cut the cause of lower rebirths!"

- Nagarjuna (in the Prajñāśataka)

"If, incidentally, you accumulate the collections and purify the obstructions, make requests to the deities and your guru, and contemplate insistently with perseverance, then even that which you think will not come about for a hundred years will come about effortlessly, for conditioned things do not remain static."

- Dölpopa

In other words; do your practice and the results will come.

Your body is adorned with the signs, so beautiful, nectar for the eyes, like a cloudless sky in autumn ornamented with clusters of stars.

O Sage, endowed with the color of gold, so beautiful, dressed in monastic robes, like a golden mountaintop wrapped in clouds at dusk or dawn.

Protector, the sphere of your face's splendor, although unadorned by jewelry, is beyond that of the full moon in a vast and cloudless sky.

If the lotus of your mouth and a lotus in bloom in the sun are beheld by a bee, the bee will have its doubts about the lotus.

Your face endowed with the color of gold is beautified further with your pure white teeth, like immaculate autumn moonbeams filtering between golden mountains.

Venerable one, your right hand, embellished with the mark of the wheel, gives breath to the people terrified by the cycle of samsāric existence.

O Sage, as you walk, your feet leave designs on the earth like resplendent lotuses.

Could Padminī be lovelier?

- Upama-stava

Nor should you look at them (The Sangha) as some kind of opponents, having made arbitrary divisions in terms of "your group" and "my group." Instead, treat them with respect as if they were the Sangha Jewel.

Exhortation to the Extraordinary Attitude says:
Those who, dwelling in forests, desire excellent qualities should not look for faults in other people; they should not produce the attitude "I'm especially noble, I'm the best."
This haughtiness is the root of all carelessness. Don't let contempt for lesser monks arise or else you won't reach liberation for an con. This is a training stage in this teaching.

- From Lama Tsongkhapa

Similarly, Lama Pabongka Rinpoche says:

“Abandoning Dharma is, in the final analysis, disparaging the Hinayana because of the Mahayana; favouring the Hinayana on account of the Mahayana; playing off sutra against tantra; playing off the four classes of the tantras against each other; favouring one of the Tibetan schools—the Sakya, Gelug, Kagyu, or Nyingma—and disparaging the rest; and so on. In other words, we abandon Dharma any time we favour our own tenets and disparage the rest”

The sin of engaging in the ten non-virtues is very small when compared to the sin of having broken one's reliance on the Dharma

- Dromtönpa (Chief Disciple of Atiśa)

Even creating a small bad deed will result in terrible fear and disasters in future lives, like having ingested poison.

Even creating a little merit will bring great happiness in future lives and accomplish vast objectives, like grains that ripen to perfection.

From: The Collection of Indicative Verses

By way of these ten virtuous paths of action, you will become a buddha. On the other hand, if one who does not guard even a single virtuous path of action throughout his life nevertheless says, "I am a Mahāyānist. I seek unsurpassed, perfectly complete enlightenment," that person is an utter hypocrite and a great liar. He is deceiving the world before the eyes of all the blessed ones and propounding nihilism. At the time of death, he will be very confused and fall in the wrong direction.

From: The Ksitigarbha Sūtra

Lord of nagas, one Dharma of bodhisattvas cuts off falling back down and being born in the lower rebirths. What is that one Dharma? It is to finely investigate with regard to virtuous qualities, thinking, "How am I doing? Am I transgressing or main-taining them day and night?"

- Questions of the Naga King Sāgara Sūtra (Sagaranāgarājapari-prcchāsútra)

Assailed by afflictions, we discover Dharma

And find the way to liberation. Thank you, evil forces!

When sorrows invade the mind, we discover Dharma

And find lasting happiness. Thank you, sorrows!

Through harm caused by spirits we discover Dharma

Through people's hate we discover Dharma

And find fearlessness. Thank you, ghosts and demons! And find benefits and happiness. Thank you, those who hate us! Through cruel adversity, we discover Dharma

And find the unchanging way. Thank you, adversity! Through being impelled to by others, we discover Dharma

And find the essential meaning. Thank you, all who drive us on!

We dedicate our merit to you all, to repay your kindness.

- Longchenpa

For how could we practice patience if there were no one who made us angry?

How could one who is not disenchanted here have any respect for peace?

- Four Hundred Stanzas (8.12)

“It is such a mistake to assume that practicing dharma will help us calm down and lead an untroubled life; nothing could be further from the truth. Dharma is not a therapy. Quite the opposite, in fact; dharma is tailored specifically to turn your life upside down—it’s what you sign up for. So when your life goes pear-shaped, why do you complain? If you practice and your life fails to capsize, it is a sign that what you are doing is not working. This is what distinguishes the dharma from New Age methods involving auras, relationships, communication, well-being, the Inner Child, being one with the universe, and tree hugging. From the point of view of dharma, such interests are the toys of samsaric beings—toys that quickly bore us senseless.”

― Dzongsar Khyentse Rinpoche

"Having seen that just as a lotus grove does not go to destruction by the falling of snowflakes so his treasures did not go to destruction through his supreme generosity, like a lordly elephant from a raging forest fire, he departed from his crying relatives and from his delightful home."

Just as lightning on a cloudy night illuminates the darkness for a moment, likewise, through the power of the buddhas, a rare wholesome thought appears in the world.

Therefore virtue is perpetually weak, while evil is very strong and quite unbearable.