The entire universe is full of miseries, and therefore the inhabitants of this material universe are always shedding tears out of intense grief. There is a great ocean of water made from such tears, but for one who surrenders unto the Supreme Personality of Godhead, the ocean of tears is at once dried up. One need only see the charming smile of the Supreme Lord. In other words, the bereavement of material existence immediately subsides when one sees the charming smile of the Lord.
(Srimad Bhagavatam-----3:28:32-----purport).

The spiritual senses are beyond the material senses. A materialist can think only of the negation of material variety; he cannot understand spiritual variety. He thinks that spiritual variety simply contradicts material variety and is a negation or void, but such conceptions cannot even reach the precincts of spiritual realization. The wonderful activities of the gross body and subtle mind are always imperfect. They are below the degree of spiritual understanding and are ephemeral. The spiritual mellow is eternally wonderful and is described as pūrṇa, śuddha, nitya-mukta—that is, complete, perfectly pure and eternally liberated from all material conceptions. When we are unable to fulfill our material desires, there is certainly sorrow and confusion. This may be described as vivarta. But in spiritual life there is no sorrow, inebriety or imperfection.
(Sri Caitanya Caritamrta-----2:8:193-----purport).

Where can one see qualities such as intelligence, knowledge, freedom from doubt, joy, sorrow, fear, fearlessness, nonviolence, equanimity, contentment, austerity, charity, fame, and infamy? These qualities are indicative of consciousness, so they are present wherever consciousness is present.
(Renunciation through Wisdom).

Therefore, O Arjuna, surrendering all your works unto Me, with full knowledge of Me, without desires for profit, with no claims to proprietorship, and free from lethargy, fight.
To achieve such a state of surrender, one has to be free from selfish desires, unaffected by dualities, and devoid of all false prestige. Dualities are born of false ego, the worst enemy of surrender. One who transcends false ego, and with it the effects of duality, is very easily freed from material desires, and then he vanquishes hate, greed, anger, fear, and so on. In the stage of full surrender to the Lord, even negative qualities like mundane desire and envy, along with dualities like hunger and thirst, heat and cold, joy and sorrow, loss and gain, sin and piety, and honor and dishonor, are converted into spiritual energy by being brought into contact with the Supreme Lord.
(Renunciation through Wisdom).

For formality's sake, when a man is lying on his deathbed, his relatives come to him, and sometimes they cry very loudly, addressing the dying man: "Oh, my father!" "Oh, my friend!" or "Oh, my husband!" In that pitiable condition the dying man wants to speak with them and instruct them of his desires, but because he is fully under the control of the time factor, death, he cannot express himself, and that causes him inconceivable pain. He is already in a painful condition because of disease, and his glands and throat are choked up with mucus. He is already in a very difficult position, and when he is addressed by his relatives in that way, his grief increases.
(Srimad Bhagavatam-----3:30:17-----purport).

According to the Vedic system, if a person dies during the daytime it is customary for his funeral ceremony to be performed before the sun sets, regardless of whether he is burned or buried, and if he dies at night the funeral must be completed before the next sunrise.
(Srimad Bhagavatam-----7:2:35-----purport).

Thus the man, who engaged with uncontrolled senses in maintaining a family, dies in great grief, seeing his relatives crying. He dies most pathetically, in great pain and without consciousness.
(Srimad Bhagavatam-----3:30:18-----translation).

Sunīti, the mother of Dhruva, was a farseeing woman, and therefore she advised her son to worship the Supreme Lord and no one else. The Lord is described herein as lotus eyed (padma-palāśa-locanāt). When a person is fatigued, if he sees a lotus flower all his fatigue can be immediately reduced to nil. Similarly, when an aggrieved person sees the lotus face of the Supreme Personality of Godhead, immediately all his grief is reduced. A lotus flower is also an insignia in the hand of Lord Viṣṇu as well as in the hand of the goddess of fortune.
(Srimad Bhagavatam-----4:8:23-----purport).

A person who is never subjected to material happiness or hatred, lamentation or ambition, who is aloof from all materially auspicious and inauspicious activities, and who is fully devoted in Kṛṣṇa consciousness—such a devotee is very dear to Lord Kṛṣṇa. A devotee who treats equally a so-called enemy and a so-called friend in the material world, who is not disturbed by heat or cold, who is without any attachment, who is equally situated when respected or insulted, who is always grave, satisfied in any condition of life, without any fixed residence, and fixed in Kṛṣṇa consciousness—such a devotee is very dear to Lord Kṛṣṇa. Even if one is not situated in the transcendental position, still, if he approves the transcendental life described here, he also becomes very dear to Kṛṣṇa.
(Teachings of Lord Caitanya).

A devotee should not be subjected to lamentation or illusion. There is the following statement in the Padma Purāṇa: "Within the heart of a person who is overpowered by lamentation or anger, there is no possibility of Kṛṣṇa's being manifested."
(Nectar of Devotion).

If one's son has died, one may certainly be affected by lamentation and illusion and cry for the dead son, but one may overcome lamentation and illusion by considering the verses of Bhagavad-gītā.
jātasya hi dhruvo mṛtyur
dhruvaṁ janma mṛtasya ca
As the soul transmigrates, one who has taken birth must give up the present body, and then he must certainly accept another body. This should be no cause for lamentation. Therefore Lord Kṛṣṇa says, dhīras tatra na muhyati: (B.G.2:13) one who is dhīra, or sober, who is learned in philosophy and established in knowledge, cannot be unhappy over the transmigration of the soul.
(Srimad Bhagavatam-----7:15:23-----purport).

Material compassion, lamentation and tears are all signs of ignorance of the real self. Compassion for the eternal soul is self-realization.
(Bhagavad-Gita-----2:1-----purport).

The material body is perishable by nature. It may perish immediately, or it may do so after a hundred years. It is a question of time only. There is no chance of maintaining it indefinitely. But the spirit soul is so minute that it cannot even be seen by an enemy, to say nothing of being killed. As mentioned in the previous verse, it is so small that no one can have any idea how to measure its dimension. So from both viewpoints there is no cause of lamentation, because the living entity as he is cannot be killed nor can the material body be saved for any length of time or permanently protected.
(Bhagavad-Gita-----2:18-----purport).

When a person becomes weak from the attack of old age, the family members, servants and secretaries do not care for him. He is then unable to counteract this. Thus he becomes more and more anxious and laments his frightful condition.
(Srimad Bhagavatam-----4:28:8-----purport).

The mind is the original cause of material bondage. It is followed by many enemies, such as anger, pride, greed, lamentation, illusion and fear. The best way to control the mind is to engage it always in Kṛṣṇa consciousness (sa vai manaḥ kṛṣṇa-padāravindayoḥ (S.B.9:4:18). Since the followers of the mind bring about material bondage, we should be very careful not to trust the mind.
(Srimad Bhagavatam-----5:6:5-----purport).

One who has taken his birth is sure to die, and after death one is sure to take birth again. Therefore, in the unavoidable discharge of your duty, you should not lament.
(Bhagavad-Gita------2:27-----translation).

A person who neither rejoices upon achieving something pleasant nor laments upon obtaining something unpleasant, who is self-intelligent, who is unbewildered, and who knows the science of God, is already situated in transcendence.
(Bhagavad-Gita------5:20-----translation).

One who neither rejoices nor grieves, who neither laments nor desires, and who renounces both auspicious and inauspicious things—such a devotee is very dear to Me. A pure devotee is neither happy nor distressed over material gain and loss, nor is he very much anxious to get a son or disciple, nor is he distressed by not getting them. If he loses anything which is very dear to him, he does not lament. Similarly, if he does not get what he desires, he is not distressed. He is transcendental in the face of all kinds of auspicious, inauspicious and sinful activities. He is prepared to accept all kinds of risks for the satisfaction of the Supreme Lord. Nothing is an impediment in the discharge of his devotional service. Such a devotee is very dear to Kṛṣṇa.
(Bhagavad-Gita------12:17-----translation and purport).

The devotee in Kṛṣṇa consciousness has nothing for which to lament or desire. Since God is full, a living entity who is engaged in God's service, in Kṛṣṇa consciousness, becomes also full in himself. He is just like a river cleansed of all dirty water. Because a pure devotee has no thought other than Kṛṣṇa, he is naturally always joyful. He does not lament for any material loss or aspire for gain, because he is full in the service of the Lord. He has no desire for material enjoyment, because he knows that every living entity is a fragmental part and parcel of the Supreme Lord and therefore eternally a servant.
(Bhagavad-Gita------18:54-----purport).

Sometimes we see that when a person is on the platform of material goodness, he is attracted more or less by the cultivation of knowledge. This is, of course, a better position, for knowledge gives one the preference to accept devotional service. Unless one comes to the platform of knowledge, the brahma-bhūta (S.B.4:30:20) stage, one cannot advance in devotional service. As Kṛṣṇa says in Bhagavad-gītā (18.54):
brahma-bhūtaḥ prasannātmā
na śocati na kāṅkṣati
samaḥ sarveṣu bhūteṣu
mad-bhaktiṁ labhate parām
"One who is thus transcendentally situated at once realizes the Supreme Brahman and becomes fully joyful. He never laments nor desires to have anything; he is equally disposed to every living entity. In that state he attains pure devotional service unto Me."
(Srimad Bhagavatam-----4:25:62-----purport).