One has to understand the Lord as the Supreme Personality of Godhead, as He was directly understood by Arjuna, Lord Kṛṣṇa's first disciple. Such understanding of Bhagavad-gītā is really profitable and authorized for the welfare of human society in fulfilling the mission of life.
(Bhagavad-gita---preface).

One should fix his mind fully on Kṛṣṇa in order to achieve Him. One should work only for Kṛṣṇa. It does not matter in what kind of work one engages, but that work should be done only for Kṛṣṇa. That is the standard of devotional service. The devotee does not desire any achievement other than pleasing the Supreme Personality of Godhead. His life's mission is to please Kṛṣṇa, and he can sacrifice everything for Kṛṣṇa's satisfaction, just as Arjuna did in the Battle of Kurukṣetra. The process is very simple: one can devote himself in his occupation and engage at the same time in chanting Hare Kṛṣṇa, Hare Kṛṣṇa, Kṛṣṇa Kṛṣṇa, Hare Hare/ Hare Rāma, Hare Rāma, Rāma Rāma, Hare Hare. Such transcendental chanting attracts the devotee to the Personality of Godhead.
(Bhagavad-gita---12:6-7----purport).

The miseries and mixed happiness of all living beings are only of different degree and quality, but no one is free from the miseries of birth, death, old age and disease. Similarly, everyone has his destined happiness also. No one can get more or less of these things simply by personal endeavors. Even if they are obtained, they can be lost again. One should not, therefore, waste time with these flimsy things; one should only endeavor to go back to Godhead. That should be the mission of everyone's life.
(Srimad Bhagavatam----1:5:18---purport).

This material world is certified by the Lord in the Bhagavad-gītā as a dangerous place full of calamities. Less intelligent persons prepare plans to adjust to those calamities without knowing that the nature of this place is itself full of calamities. They have no information of the abode of the Lord, which is full of bliss and without trace of calamity. The duty of the sane person, therefore, is to be undisturbed by worldly calamities, which are sure to happen in all circumstances. Suffering all sorts of unavoidable misfortunes, one should make progress in spiritual realization because that is the mission of human life. The spirit soul is transcendental to all material calamities; therefore, the so-called calamities are called false. A man may see a tiger swallowing him in a dream, and he may cry for this calamity. Actually there is no tiger and there is no suffering; it is simply a case of dreams. In the same way, all calamities of life are said to be dreams.
(Srimad Bhagavatam----1:8:25---purport).

This life is a chance for the conditioned soul to regain his eternal God consciousness and thus fulfill the mission of life.
(Srimad Bhagavatam----2:1:36---purport).

Human life is meant for reviving one's eternal relation with the Lord, and all religious injunctions are meant for awakening this dormant instinct of the living entity. The sooner this awakening is brought about, the quicker the mission of human life is fulfilled.
(Srimad Bhagavatam----3:2:2---purport).

Knowledge means to know that the mission of the human form of life is to end all the miseries of material existence.
(Srimad Bhagavatam----3:3:19---purport).

Devotees are expected to carry the message or desire of the Lord to such conditioned souls and enlighten them with Kṛṣṇa consciousness. Thus they may be elevated to transcendental, spiritual life, and the mission of their lives will be successful.
(Srimad Bhagavatam----3:29:23---purport).

Every devotee should be determined that in this life he will be able to satisfy the Supreme Personality of Godhead and by that process go back home, back to Godhead. That is the perfection of the highest mission of life.
(Srimad Bhagavatam----4:8:69---purport).

When the Lord is pleased with one's service, one's mission in life is fulfilled.
(Srimad Bhagavatam----4:20:9---purport).

The real mission of life for the conditioned soul is to reestablish the forgotten relationship with the Supreme Personality of Godhead.
(Srimad Bhagavatam----5:14:40---purport).

Uncontaminated, pure religion consists of understanding one's relationship with God and acting accordingly, thus fulfilling the highest mission of life and returning home, back to Godhead.
(Srimad Bhagavatam----7:7:15---purport).

Although the purpose of life is to become spiritually rich, unfortunate men, misguided as they are, are always engaged in trying to become materially rich. Such material engagements, however, do not help one in the actual fulfillment of the human mission.
(Srimad Bhagavatam----7:15:29---purport).

The real mission of human life is to get free from encagement in the material body. Therefore Kṛṣṇa descends to teach the conditioned soul about spiritual realization and how to become free from material bondage.
(Srimad Bhagavatam----9:9:20---purport).

Anyone who, because of his background of pious activities in previous lives, is anxious to hear Śrīmad-Bhāgavatam immediately realizes the presence of the Supreme Lord within his heart and fulfills the mission of his life.
(Sri Caitanya Caritamrta----1:1:91----purport).

The person who actually wants perfect fulfillment of the mission of human life should simply worship Lord Kṛṣṇa, and that will simplify the matter and completely guarantee the success of his human life.
(Krsna Book).