Srimad Bhagavad-Gita, Chap 12, Verses 1 & 2:

arjuna uvächa evam satata-yuktä ye bhaktäs tväm paryupäsate ye chäpy aksharam avyaktam teshäm ke yoga-vittamäh

"Arjuna inquired: Who are considered to be more perfect: those who are properly engaged in Your devotional service, or those who worship the impersonal Brahman, the unmanifested?"

In the Bhagavad-Gita, Krishna has explained about the personal, the impersonal and the universal and has described all kinds of devotees and yogis. Generally, the transcendentalists can be divided into two classes. One is the impersonalist, and the other is the personalist. The personalist devotee engages himself with all energy in the service of Krishna. The impersonalist engages himself not directly in the service of Krishna but in meditation on the impersonal Brahman, the unmanifested. Arjuna is here questioning which position is better. There are different ways to realize the Absolute Truth, but Krishna indicates in this chapter that bhakti-yoga, or devotional service to Him, is highest of all. It is the most direct, and it is the easiest means for association with the Godhead.

Throughout the Gitä personal devotion to Krishna is recommended as the highest form of spiritual realization. Yet there are those who are still attracted to Krishna's impersonal brahmajyoti effulgence, which is the all-pervasive aspect of the Absolute Truth and which is unmanifest and beyond the reach of the senses. Arjuna would like to know which of these two types of transcendentalists is more perfect in knowledge.

shri-bhagavän uvächa mayy äveshya mano ye mäm nitya-yuktä upäsate shraddhayä parayopetäs te me yuktatamä matäh

"The Blessed Lord said: He whose mind is fixed on My personal form, always engaged in worshiping Me with great and transcendental faith, is considered by Me to be most perfect."

In answer to Arjuna's question, Krishna clearly says that he who concentrates upon His personal form and who worships Him with faith and devotion is to be considered most perfect in yoga. Thus, we find here that of the different processes for realization of the Absolute Truth, bhakti-yoga, or devotional service, is the highest. If one at all desires to have the association of the Supreme Personality of Godhead, then he must take to devotional service.