Attachment means accepting things for one's own sense gratification, and detachment is the absence of such sensual attachment. But one fixed in Kṛṣṇa consciousness has neither attachment nor detachment because his life is dedicated in the service of the Lord. Consequently he is not at all angry even when his attempts are unsuccessful. Success or no success, a Kṛṣṇa conscious person is always steady in his determination.
(Bhagavad-Gita--2:56---purport).

One should always think of Kṛṣṇa and not forget Him even for a moment. Concentration of the mind on the Supreme is called samādhi, or trance. In order to concentrate the mind, one should always remain in seclusion and avoid disturbance by external objects. He should be very careful to accept favorable and reject unfavorable conditions that affect his realization. And, in perfect determination, he should not hanker after unnecessary material things that entangle him by feelings of possessiveness.
(Bhagavad-Gita--6:10).

One should engage oneself in the practice of yoga with determination and faith and not be deviated from the path. One should abandon, without exception, all material desires born of mental speculation and thus control all the senses on all sides by the mind.
(Bhagavad-Gita---6:24---translation).

The yoga practitioner should be determined and should patiently prosecute the practice without deviation. One should be sure of success at the end and pursue this course with great perseverance, not becoming discouraged if there is any delay in the attainment of success. One can execute the process of bhakti-yoga successfully with full-hearted enthusiasm, perseverance, and determination, by following the prescribed duties in the association of devotees and by engaging completely in activities of goodness. As for determination, one should follow the example of the sparrow who lost her eggs in the waves of the ocean. A sparrow laid her eggs on the shore of the ocean, but the big ocean carried away the eggs on its waves. The sparrow became very upset and asked the ocean to return her eggs. The ocean did not even consider her appeal. So the sparrow decided to dry up the ocean. She began to pick out the water in her small beak, and everyone laughed at her for her impossible determination. The news of her activity spread, and at last Garuḍa, the gigantic bird carrier of Lord Viṣṇu, heard it. He became compassionate toward his small sister bird, and so he came to see the sparrow. Garuḍa was very pleased by the determination of the small sparrow, and he promised to help. Thus Garuḍa at once asked the ocean to return her eggs lest he himself take up the work of the sparrow. The ocean was frightened at this, and returned the eggs. Thus the sparrow became happy by the grace of Garuḍa.
(Bhagavad-Gita---6:24---purport).

Steadiness means that one should be very determined to make progress in spiritual life. Without such determination, one cannot make tangible progress. And self-control means that one should not accept anything which is detrimental to the path of spiritual progress. One should become accustomed to this and reject anything which is against the path of spiritual progress.
(Bhagavad-Gita----13:8-12---purport).

A neophyte devotee must faithfully serve the pure devotee, and he should be very much obedient and strictly follow the instructions. These are the signs of a devotee who is determined to achieve success even in the existing duration of life.
(Srimad Bhagavatam---1:5:29---purport).

The soul is the occupant of the chariot of the body, of which the driver is the intelligence. The mind is the determination to reach the destination, the senses are the horses, and the sense objects are also included in that activity. Thus one can reach the destination, Viṣṇu, who is paramaṁ padam, the supreme goal of life. In conditioned life the consciousness in the body is the cause of bondage, but the same consciousness, when transformed into Kṛṣṇa consciousness, becomes the cause for one's returning home, back to Godhead.
(Srimad Bhagavatam----7:15:41---purport).