Kapiladeva instructs that we should not endeavor hard for things which may come automatically, without extraneous labor. The exact word used in this connection, yadṛcchayā, means that every living entity has a predestined happiness and distress in his present body; this is called the law of karma. It is not possible that simply by endeavors to accumulate more money a person will be able to do so, otherwise almost everyone would be on the same level of wealth. In reality everyone is earning and acquiring according to his predestined karma. According to the Bhāgavatam conclusion, we are sometimes faced with dangerous or miserable conditions without endeavoring for them, and similarly we may have prosperous conditions without endeavoring for them. We are advised to let these things come as predestined.
(Srimad Bhagavatam-----3:27:8-----purport).

That is the symptom of a person making progress on the path of Kṛṣṇa consciousness. It is said that a devotee in Kṛṣṇa consciousness never takes any miserable condition of life to be condemnation by the Supreme Personality of Godhead. He accepts the miserable condition to be the grace of the Lord. He thinks, "I would have been punished or put into a more dangerous condition of life due to my past misdeeds, but the Lord has protected me. Thus I have received only a little punishment as token execution of the law of karma." Thinking of His grace in that way, a devotee always surrenders to the Supreme Personality of Godhead more and more seriously and is not disturbed by such so-called punishment.
(Srimad Bhagavatam-----4:7:15-----purport).

Everything was created by Brahmā in the beginning. Regarding Nārada, it is understood that because his previous life was very pious and his association very good, he was born as Nārada. Others were also born in their own capacities, according to their backgrounds. The law of karma continues birth after birth, and when there is a new creation, the same karma comes back with the living entities. They are born in different capacities according to karma even though their father is originally Brahmā, who is the exalted qualitative incarnation of the Supreme Personality of Godhead.
(Srimad Bhagavatam-----4:8:2-----purport).

The same fact is explained in Bhagavad-gītā Yajñārthāt karmaṇo 'nyatra: one should perform karma only for the purpose of satisfying the Supreme Lord, otherwise one is bound by the action and reaction of karma. Under the laws of karma a living entity wanders within the universe under the rule of eternal time, and sometimes he becomes a mosquito and sometimes Lord Brahmā. To a sane man this business is not very fruitful. Bhagavad-gītā (9.25) gives a warning to the living entities: yānti deva-vratā devān—those who are addicted to the worship of the demigods go to the planets of the demigods, and those who are addicted to worship of the Pitās, forefathers, go to the Pitās.
(Srimad Bhagavatam-----4:11:21-----purport).

Those who are inclined to material activities remain in the material sphere. But persons who engage in devotional service reach the abode of the Supreme Personality of Godhead, where there is neither birth nor death nor different varieties of life under the influence of the law of karma. The best interest of the living entity is to engage himself in devotional service and go back home, back to Godhead. Śrīla Bhaktivinoda Ṭhākura advised: "My friend, you are being washed away in material nature's waves of time. Please try to understand that you are the eternal servant of the Lord. Then everything will stop, and you will be eternally happy."
(Srimad Bhagavatam-----4:11:21-----purport).

When living entities, therefore, are viewed in the bodily concept of life, one appears to be different from another. Lord Manu wanted to change the vision of Dhruva Mahārāja, who was looking upon the Yakṣas as different from him or as his enemies. Factually no one is an enemy or a friend. Everyone is passing through different types of bodies under the law of karma, but as soon as one is situated in his spiritual identity, he does not see differentiation in terms of this law.
(Srimad Bhagavatam-----4:11:29-----purport).

The saintly sages elected King Vena to become king, but he proved to be mischievous; therefore the sages were very much afraid of incurring sinful reaction. Thelaw of karma prohibits a person even to associate with a mischievous individual. By electing Vena to the throne, the saintly sages certainly associated with him. Ultimately King Vena became so mischievous that the saintly sages actually became afraid of becoming contaminated by his activities. Thus before taking any action against him, the sages tried to pacify and correct him so that he might turn from his mischief.
(Srimad Bhagavatam-----4:14:11-----purport).

This is called punar bhavaḥ. When the gross body is finished, the plans of the living entity are taken by the mind, and by the grace of the Lord, the living entity gets a chance to give these plans shape in the next life. This is known as the law of karma. As long as the mind is absorbed in the laws of karma, a certain type of body must be accepted in the next life.
Karma is the aggregate of fruitive activities conducted to make this body comfortable or uncomfortable. We have actually seen that when one man was about to die he requested his physician to give him a chance to live four more years so that he could finish his plans.
(Srimad Bhagavatam-----4:29:62-----purport).

The subtle laws of karma, which are controlled by the Supreme, cannot be understood by ordinary conditioned souls. Therefore Kṛṣṇa says that one who can understand Him and how He is acting, controlling everything by subtle laws, immediately becomes freed by His grace. That is the statement of Brahma-saṁhitā (karmāṇi nirdahati kintu ca bhakti-bhājām (Bs. 5.54)). One should take to devotional service without reservations and surrender everything to the supreme will of the Lord. That will make one happy in this life and the next.
(Srimad Bhagavatam-----6:14:55-----purport).

According to the Vedic injunctions, one must accept a wife just to beget a son who can deliver one from the clutches of Yamarāja. Unless one has a son to offer oblations to the pitās, or forefathers, one must suffer in Yamarāja's kingdom. King Citraketu was very much aggrieved. thinking that because his son was going away with Yamarāja he himself would again suffer. The subtle laws exist for the karmīs; if one becomes a devotee, he has no more obligations to the laws of karma.
(Srimad Bhagavatam-----6:14:56-----purport).