The fruitive workers cannot be counted among the yogīs. The actual yogīs are the karma-yogīs, the jñāna-yogīs, the aṣṭāṅga-yogīs, and the bhakti-yogīs. Factually they are the same, although named differently. The yogic process is like a ladder one ascends gradually toward the final goal of the Absolute Truth. Niṣkāma-karma, or renunciation of the fruits of one's labor, is the first step on this ladder. When knowledge and austerity are added to it, it becomes jñāna-yoga, the second step in this ladder. And when meditation on the Supreme is added to jñāna-yoga, the third step is reached, namely aṣṭāṅga-yoga. Finally, when loving devotional service to the Supreme Lord is practiced along with aṣṭāṅga-yoga, it is transformed into bhakti-yoga. This entire successive process is yoga. For an exact and clear delineation of the subject of yoga, all four steps need to be explained separately. Those who desire the best for humanity take to the path of yoga. The process for progressing in yoga requires, first, determination and strict execution of discipline at each stage. When a person is firmly situated at one stage, he then has to relinquish attachment and adherence to the practices of that stage in order to elevate himself to the next higher stage. Those who cannot reach the top for some reason and get stuck at any one of the four stages acquire the designation of that particular stage. Thus there are karma-yogīs, jñāna-yogīs, aṣṭāṅga-yogīs, and bhakta-yogīs. Lord Kṛṣṇa instructs Arjuna that one who renders loving devotional service to Him, the Supreme Lord, is the highest among all yogīs, and that Arjuna should thus strive to become such a bhakti-yogī.
The successive, step-by-step spiritual path is not the same as step-by-step progress in the material world. In the mundane process the rules of progress are strict and cannot be transgressed. If one wants to acquire a doctorate at a university, he has to begin from the elementary school level and gradually work upwards. It is impossible to go directly to the university without prior schooling. In spiritual life, however, although there are strict regulations, by the Supreme Lord's grace one can bypass many intermediary stages and reach the top, or "doctorate" level. One can attain this divine grace by intimate and constant association with the Supreme Lord. And such intimate association with the Lord comes about through confidential exchanges with a pure devotee of the Supreme Lord. Everyone of us is intimately and eternally related to the Supreme Lord, but due to the bad influence of māyā we have forgotten our relationship with Him.