Just fix your mind upon Me, the Supreme Personality of Godhead, and engage all your intelligence in Me. Thus you will live in Me always, without a doubt. One who is engaged in Lord Kṛṣṇa's devotional service lives in a direct relationship with the Supreme Lord, so there is no doubt that his position is transcendental from the very beginning. A devotee does not live on the material plane—he lives in Kṛṣṇa. The holy name of the Lord and the Lord are nondifferent; therefore when a devotee chants Hare Kṛṣṇa, Kṛṣṇa and His internal potency are dancing on the tongue of the devotee. When he offers Kṛṣṇa food, Kṛṣṇa directly accepts these eatables, and the devotee becomes Kṛṣṇa-ized by eating the remnants. One who does not engage in such service cannot understand how this is so, although this is a process recommended in the Bhagavad-gītā and in other Vedic literatures.
(Bhagavad-Gita------10:8------ translation and purport).

Perfection in yoga, therefore, is marked by the awakening of spiritual bliss. And when one is strongly drawn to this blissful state, one attains to the transcendental abode of the Supreme Lord. Iron in constant touch with fire develops the properties of fire. Similarly, when the jīva in the material nature rises to the state of spiritual bliss by means of devotional service, his spiritual consciousness awakens and he becomes oblivious of this phenomenal world. In the Bhagavad-gītā (12.8-9) Lord Kṛṣṇa tells us how to increase the influence of His spiritual energy upon us:
mayy eva mana ādhatsva
mayi buddhiṁ niveśaya
nivasiṣyasi mayy eva
ata ūrdhvaṁ na saṁśayaḥ
atha cittaṁ samādhātuṁ
na śaknoṣi mayi sthiram
abhyāsa-yogena tato
mām icchāptuṁ dhanañjaya
Just fix your mind upon Me, the Supreme Personality of Godhead, and engage all your intelligence in Me. Thus you will live in Me always, without a doubt. My dear Arjuna, O winner of wealth, if you cannot fix your mind upon Me without deviation, then follow the regulative principles of bhakti-yoga. In this way you will develop a desire to attain Me.
When a person fixes his mind on the eternal, exquisite form of Śyāmasundara, the blackish, beautiful Lord Kṛṣṇa, all distress and anguish are vanquished. In the initial stages, the attempt to fix the mind on Kṛṣṇa may be unsuccessful, but with regulated practice (abhyāsa-yoga) it becomes possible. Abhyāsa-yoga means sincere engagement in the ninefold process of bhakti, beginning with hearing and chanting the holy name, pastimes, and so on, of Lord Kṛṣṇa. Proper execution of abhyāsa-yoga culminates in the awakening of divine consciousness, or superconsciousness. This is true success.
(Renunciation through Wisdom).